BASIC OF COMPUTER FUNDAMENTAL BY AKSHAY SHELKE (NEVER WIN..!)

BASIC OF COMPUTER FUNDAMENTAL
BY AKSHAY SHELKE (NEVER WIN..!)

1) What is Computer?

As per our basic knowledge, an electronic device that accepts input/data and processes it into valuable information i.e. output is named a Computer.

- Basic Block Diagram of Computer

No matter which company the computer has been manufactured, the basic components of the computer and working remain the same. The computer consists 4 main units-

- Functionalities of a Computer

If we look at it in a very broad sense, any digital computer carries out the following five functions −

Step 1 − Takes data as input.

Step 2 − Stores the data/instructions in its memory and uses them as required.

Step 3 − Processes the data and converts it into useful information.

Step 4 − Generates the output.

Step 5 − Controls all the above four steps.

- Generations of Computer

There exist 5 computer generations till date. In the following list, approximate dates against each generation have been mentioned, which are normally accepted. These five generations of computers are based on their processing hardware.

Generations	Period	Technology Used
First Generation	1946-1959	Vacuum tube-based
Second Generation	1959-1965	Transistor-based
Third Generation	1965-1971	Integrated Circuit based
Fourth Generation	1971-1980	VLSI microprocessor-based
Fifth Generation	1980-onwards	ULSI microprocessor-based

2) Computer Hardware

· Motherboard

-A computer is an electronic device that processes the data with respect to the user’s requirements using IO devices. The data processing takes place in a processor, an important component. The processor is situated in a hardware circuit board called the motherboard or printed circuit board (PCB).

It connects the CPU, memory, hard drives, optical drives, video card, sound card, and other parts. It also connects expansion cards directly or via cables.

· Central Processing Unit (CPU)

-A Central Processing Unit is the most important component of a computer system. A CPU is a hardware that performs data input/output, processing and storage functions for a computer system. A CPU can be installed into a CPU socket. These sockets are generally located on the motherboard. CPU can perform various data processing operations. CPU can store data, instructions, programs, and intermediate results.

· Random Access Memory (RAM)

-A computer is an electronic device, but it is very similar to a Human Brain. The human brain has memory, and it is the most essential part played by the brain, memory helps in remembering things, and people remember their past due to the memory present in the brain, similarly, computers have memory too.

RAM	ROM
Definition of RAM is Random Access Memory	Definition of ROM is Read-only Memory
Random Access Memory (RAM) is expensive when compared to ROM	ROM is cheaper when compared to RAM.
The speed of Random Access Memory (RAM) is higher when compared to ROM	The speed of Read-only Memory (ROM) is slower when compared to RAM.
Random Access Memory (RAM) has a higher capacity when compared to ROM	ROM has a lower capacity compared to RAM
Data in RAM can be modified, erased, or read.	Data in ROM can only be read, it cannot be modified or erased.
The data stored in RAM is used by the Central Processing Unit (CPU) to process current instructions	The data stored in ROM is used to bootstrap the computer.
Data stored on RAM can be accessed by the Central Processing Unit.	If the Central Processing Unit (CPU) needs to access the data on ROM, first the data must be transferred to RAM, and then the Central Processing Unit (CPU) will be able to access the data.
Data of RAM is very volatile, it will exist as long as there is no interruption in power.	Data present in Read-Only Memory (ROM) is not volatile, it is permanent. Data will remain unchanged even when there is a disruption in the power supply.

· Hard Disk Drives (HDD)

-an internal storage medium like a hard disk that is fixed inside the computer.

- What is a Hard Disk Drive?

A hard disk is a memory storage device that looks like this:

The disk is divided into tracks. Each track is further divided into sectors. The point to be noted here is that outer tracks are bigger in size than the inner tracks but they contain the same number of sectors and have equal storage capacity. This is because the storage density is high in sectors of the inner tracks whereas the bits are sparsely arranged in sectors of the outer tracks. Some space of every sector is used for formatting. So, the actual capacity of a sector is less than the given capacity.

Read-Write(R-W) head moves over the rotating hard disk. It is this Read-Write head that performs all the read and writes operations on the disk and hence, the position of the R-W head is a major concern. To perform a read or write operation on a memory location, we need to place the R-W head over that position.

Some important terms must be noted here:

1. Seek time – The time taken by the R-W head to reach the desired track from its current position.

2. Rotational latency – Time is taken by the sector to come under the R-W head.

3. Data transfer time – Time is taken to transfer the required amount of data. It depends upon the rotational speed.

4. Controller time – The processing time taken by the controller.

5. Average Access time – seek time + Average Rotational latency + data transfer time + controller time.

Note: Average Rotational latency is mostly 1/2*(Rotational latency).

Hard Disk Drive Storage Capacity

Ø Three storage options 16 GB, 32 GB, and 64 GB. This is one of the lowest HDD storage space ranges and is often seen in older and smaller devices.

Ø There are two sizes 120 GB and 256 GB. This category is commonly regarded as an entry level for HDD devices like as laptops or desktops.

Ø 500 GB, 1 TB, and 2 TB are available. HDD storage of 500 GB or more is often deemed adequate for the average user. With this much capacity, users can most certainly save all of their music, photos, videos, and other information. Individuals with large-file games should find 1 TB to 2 TB of HDD capacity adequate.

Ø More than 2 TB of storage. Anything with more than 2 TB of HDD space is appropriate for users who work with high-resolution files.

Ø Recently, the highest capacity of HDD is 20 TB.

· Solid State Drives (SSD)

-Solid-state drive (SSD) is a solid-state storage device that uses integrated circuit assemblies as memory to store data. SSD is also known as a solid-state disk although SSDs do not have physical disks.
There are no moving mechanical components in SSD. This makes them different from conventional electromechanical drives such as hard disk drives (HDDs) or floppy disks, which contain movable read/write heads and spinning disks.

Solid State Drive vs Hard Disk Drives

Parameter	HDD	SSD
Long term storage	HDDs are more reliable for long-term storage.	SSDs are comparatively less reliable for long-term storage due to data leaks that can occur if kept unpowered for more than a year.
Access speed	The data accessing speed is slower as compared to SSD.	The data accessing speed is much higher as compared to HDD.
Performance	The performance suffers because of fragmentation.	The performance does not suffer because of fragmentation.
Suitable for	HDDs are suitable for · Extensive storage · Long-term storage	SSDs are suitable for · Fast data retrieval · Laptop or desktop because of low power consumption and size.

· Computer Peripherals (Keyboard, Mouse, Monitor, etc.)

-Examples of Hardware are the following −

Ø Input devices − keyboard, mouse, etc.

Ø Output devices − printer, monitor, etc.

Ø Secondary storage devices − Hard disk, CD, DVD, etc.

Ø Internal components − CPU, motherboard, RAM, etc.

Relationship between Hardware and Software

Ø Hardware and software are mutually dependent on each other. Both of them must work together to make a computer produce a useful output.

Ø Software cannot be utilized without supporting hardware.

Ø Hardware without a set of programs to operate upon cannot be utilized and is useless.

Ø To get a particular job done on the computer, relevant software should be loaded into the hardware.

Ø Hardware is a one-time expense.

Ø Software development is very expensive and is a continuing expense.

Ø Different software applications can be loaded on a hardware to run different jobs.

Ø A software acts as an interface between the user and the hardware.

Ø If the hardware is the 'heart' of a computer system, then the software is its 'soul'. Both are complementary to each other.

3) Characteristics of Ports

A port has the following characteristics −

Ø External devices are connected to a computer using cables and ports.

Ø Ports are slots on the motherboard into which a cable of external device is plugged in.

Ø Examples of external devices attached via ports are the mouse, keyboard, monitor, microphone, speakers, etc.

Let us now discuss a few important types of ports −

Ø Serial Port

Used for external modems and older computer mouse
Two versions: 9 pin, 25 pin model
Data travels at 115 kilobits per second

Ø Parallel Port

Used for scanners and printers
Also called printer port
25 pin model
IEEE 1284-compliant Centronics port

Ø PS/2 Port

Used for old computer keyboard and mouse
Also called mouse port
Most of the old computers provide two PS/2 port, each for the mouse and keyboard
IEEE 1284-compliant Centronics port

Ø Universal Serial Bus (or USB) Port

It can connect all kinds of external USB devices such as external hard disk, printer, scanner, mouse, keyboard, etc.
It was introduced in 1997.
Most of the computers provide two USB ports as minimum.
Data travels at 12 megabits per seconds.
USB compliant devices can get power from a USB port.

Ø VGA Port

Connects monitor to a computer's video card.
It has 15 holes.
Similar to the serial port connector. However, serial port connector has pins, VGA port has holes.

Ø Power Connector

Three-pronged plug.
Connects to the computer's power cable that plugs into a power bar or wall socket.

Ø Firewire Port

Transfers large amount of data at very fast speed.
Connects camcorders and video equipment to the computer.
Data travels at 400 to 800 megabits per seconds.
Invented by Apple.
It has three variants: 4-Pin FireWire 400 connector, 6-Pin FireWire 400 connector, and 9-Pin FireWire 800 connector.

Ø Modem Port

Connects a PC's modem to the telephone network.

Ø Ethernet Port

Connects to a network and high speed Internet.
Connects the network cable to a computer.
This port resides on an Ethernet Card.
Data travels at 10 megabits to 1000 megabits per seconds depending upon the network bandwidth.

Ø Game Port

Connect a joystick to a PC
Now replaced by USB

Ø Digital Video Interface, DVI port

Connects Flat panel LCD monitor to the computer's high-end video graphic cards.
Very popular among video card manufacturers.

Ø Sockets

Sockets connect the microphone and speakers to the sound card of the computer.

4) SYSTEM SOFTWARE

Software is a set of programs, which is designed to perform a well-defined function. A program is a sequence of instructions written to solve a particular problem.

There are two types of software −

System Software
Application Software

Some examples of system software are Operating System, Compilers, Interpreter, Assemblers, etc.

Here is a list of some of the most prominent features of a system software −

Close to the system
Fast in speed
Difficult to design
Difficult to understand
Less interactive
Smaller in size
Difficult to manipulate
Generally written in low-level language

Ø Application Software

Application software products are designed to satisfy a particular need of a particular environment. All software applications prepared in the computer lab can come under the category of Application software.

Application software may consist of a single program, such as Microsoft's notepad for writing and editing a simple text. It may also consist of a collection of programs, often called a software package, which work together to accomplish a task, such as a spreadsheet package.

Examples of Application software are the following −

Payroll Software
Student Record Software
Inventory Management Software
Income Tax Software
Railways Reservation Software
Microsoft Office Suite Software
Microsoft Word
Microsoft Excel
Microsoft PowerPoint

Features of application software are as follows −

Close to the user
Easy to design
More interactive
Slow in speed
Generally written in high-level language
Easy to understand
Easy to manipulate and use
Bigger in size and requires large storage space

The Operating System is a program with the following features −

An operating system is a program that acts as an interface between the software and the computer hardware.
It is an integrated set of specialized programs used to manage overall resources and operations of the computer.
It is a specialized software that controls and monitors the execution of all other programs that reside in the computer, including application programs and other system software.

Objectives of Operating System

The objectives of the operating system are −

To make the computer system convenient to use in an efficient manner.
To hide the details of the hardware resources from the users.
To provide users a convenient interface to use the computer system.
To act as an intermediary between the hardware and its users, making it easier for the users to access and use other resources.
To manage the resources of a computer system.
To keep track of who is using which resource, granting resource requests, and mediating conflicting requests from different programs and users.
To provide efficient and fair sharing of resources among users and programs.

Characteristics of Operating System

Here is a list of some of the most prominent characteristic features of Operating Systems −

Memory Management − Keeps track of the primary memory, i.e. what part of it is in use by whom, what part is not in use, etc. and allocates the memory when a process or program requests it.
Processor Management − Allocates the processor (CPU) to a process and deallocates the processor when it is no longer required.
Device Management − Keeps track of all the devices. This is also called I/O controller that decides which process gets the device, when, and for how much time.
File Management − Allocates and de-allocates the resources and decides who gets the resources.
Security − Prevents unauthorized access to programs and data by means of passwords and other similar techniques.
Job Accounting − Keeps track of time and resources used by various jobs and/or users.
Control Over System Performance − Records delays between the request for a service and from the system.
Interaction with the Operators − Interaction may take place via the console of the computer in the form of instructions. The Operating System acknowledges the same, does the corresponding action, and informs the operation by a display screen.
Error-detecting Aids − Production of dumps, traces, error messages, and other debugging and error-detecting methods.
Coordination Between Other Software and Users − Coordination and assignment of compilers, interpreters, assemblers, and other software to the various users of the computer systems.

Differences between Hardware and Software

Hardware	Software
Hardware is further divided into four main categories: Input Devices Output Devices Secondary Storage Devices Internal Components	Software is further divided into two main categories: Application Software System Software
Developed using electronic and other materials	Developed writing using instructions using a programming language
When damaged, it can be replaced with a new component	When damaged it can be installed once more using a backup copy
Hardware is physical in nature and hence one can touch and see hardware	The software cannot be physically touched but still can be used and seen
Hardware cannot be infected by Viruses	The software can be infected by Viruses
Hardware will physically wear out over time	Software does not wear out but it can be affected by bugs and glitches
An example of Hardware is hard drives, monitors, CPU, scanners, printers etc.	An example of software is Windows 10, Adobe Photoshop, Google Chrome etc.

5) Applications of Computer Fundamentals

1. Software Development: Computer fundamentals are fundamental to software development. Understanding programming languages, algorithms, data structures, and software design principles are crucial for developing applications, websites, and software systems. It forms the basis for creating efficient and functional software solutions.

2. Network Administration: Computer fundamentals are essential for network administrators. They help set up and manage computer networks, configure routers and switches, troubleshoot network issues, and ensure reliable connectivity. Knowledge of computer fundamentals enables network administrators to maintain and optimize network performance.

3. Cybersecurity: Computer fundamentals are at the core of cybersecurity. Understanding the basics of computer networks, operating systems, encryption techniques, and security protocols helps professionals protect systems from cyber threats. It enables them to identify vulnerabilities, implement security measures, and respond effectively to security incidents.

4. Data Analysis: Computer fundamentals are necessary for data analysis and data science. Knowledge of programming, statistical analysis, and database management is essential to extract insights from large datasets. Understanding computer fundamentals helps in processing and analyzing data efficiently, enabling data-driven decision-making.

5. Artificial Intelligence and Machine Learning: Computer fundamentals provide the foundation for AI and machine learning. Concepts such as algorithms, data structures, and statistical modelling are vital in training and developing intelligent systems. Understanding computer fundamentals allows professionals to create AI models, train them on large datasets, and apply machine learning techniques to solve complex problems.

6) Operating System

An operating system is an interface between the user and the software of the computer. The user gives commands through the hardware and the computer understands it, through the OS.

It is a link of computer hardware to the computer’s software and thus helping in perform functions in real-time. Some of the major examples of OS are – Microsoft, Mac OS, Linux.

Characteristics of the operating system

Memory management – As the name suggests it is responsible for the management of the memory of the computer. The OS handles both, the primary and secondary memory. The OS performs the allocation and deallocation of memory for different processes in the computer.
Device management -It also maintains the input/output traffic. Multiple inputs enter simultaneously. The OS decides which input needs to be processed first and which last. Accordingly, it assigns a particular process with the I/O device.
Processor management – There are always multiple processes going inside the computer simultaneously. The OS prioritizes and schedules the processes. It also assigns the time required to perform each process. It maintains the real-time status of the process. If one process is complete it schedules the next process in the pipeline.
File management – The computer stores all its files in a specific manner. The key function of the OS is to access these files in the fastest and the most efficient manner such that there is no delay in the execution of any program.
Security – The OS is not only responsible for storing and managing data, but also securing it. The OS has a built-in module that prevents any unauthorized access to the private data of the user.
Deadlock prevention – There are times when a single drive handles multiple processes. A deadlock situation occurs when a process enters into a waiting state. Meanwhile, the drive is held by another process. . Therefore, OS keeps a real-time check on all processes to prevent a deadlock situation.

7) Computer Networking

When multiple computer systems are connected over through a communication channel to share information and resources it is called a computer network.

Computer networks can be classified based on requirements.

Classifications of computer network

WAN – WAN or Wide Area Network is the connection of computers over a large geographical area such as a state, country, or even whole wide world. The WAN uses various types of communication channels like airwaves, telephone lines, or airwaves to interconnect different computer systems.
LAN – LAN or the local area network is the connection of computers over a restricted area. Such as a school, university campus, an office building. Any geographical area within the radius of 10kms.
MAN – MAN or the metropolitan area network connects computers over a large city or campus.
PAN – PAN stands for personal area network. These devices connected belong to a single user. Such as pc connected to the printer, fax machine, video game console, etc. which can be connected both with wires and wirelessly.

Classification of Computer Network Based on Topology

The computer network can also be classified based on its topology. Topology is the spatial arrangement of computers. The arrangement is –

Bus topology – The computers connected to a single communication line. Moreover, this one is less expensive to install as it contains only a single line.
Star topology – The computers are connected to a single point or hub, and the arrangement looks like a star thus the name. this topology is the easiest to build and implement.
Ring topology – A ring topology can be imagined as a bus topology in a closed loop. The first and last of computers are connected to form a ring. The resource is shared from one system to another with intermediate systems in between.
Mesh topology – In this, each computer is connected creating a mesh or a net-like structure.

8) Advantages of Computer

High Speed

· The computer is a very fast device.

· It can perform the calculation of a very huge amount of data.

· The computer has units of speed in a microsecond, nanosecond, and even the picosecond.

· It can process millions of computational calculations in a fraction of seconds, unlike the man who may spend many months performing the same task.

Accuracy

· In addition to being very fast, computers are very accurate.

· The calculations are 100% error-free.

· Computers perform all jobs with 100% accuracy provided that the input is correct.

Storage Capability

· Memory is a very important characteristic of computers.

· A computer has much more storage capacity than human beings.

· It can store a large amount of data.

· It can store any type of data such as images, videos, text, audio, etc.

Diligence

· Unlike human beings, a computer is free from monotony, tiredness, and lack of concentration.

· It can work continuously without any error and boredom.

· It can perform repetitive tasks with the same speed and accuracy.

Versatility

· A computer is a very versatile machine.

· A computer is very flexible in performing the jobs to be done.

· This machine can be used to solve problems related to various fields.

· At one moment, it may be processing and simplifying a complex scientific problem, and the very next moment it may be running a card game.

Reliability

A computer is a reliable machine.
Modern electronic components have long lives.
Computers are designed to make maintenance easy.

Automation

· A computer is an automatic machine.

· Automation is the capability due to which a machine can perform its task without the need for human consideration. Once the program is fed to the computer i.e., the program is held in the computer memory, then the program and instruction can be executed in absence of human consideration.

Reduction in Paperwork and Cost

· With the help of computers for data processing in an organization, there is a reduction of paperwork and results in speeding up the process, which in return saves trees.

· Because data saved as electronic files can be retrieved whenever required, the headache of maintaining piles of paper files gets reduced.

· While the investment at the beginning for the installation of a computer is high, it substantially reduces the cost of each of its transactions.

9) What is a Computer Virus?

A computer virus is a program which can harm our device and files and infect them for no further use. When a virus program is executed, it replicates itself by modifying other computer programs and instead enters its own coding. This code infects a file or program and if it spreads massively, it may ultimately result in crashing of the device.

Across the world, Computer viruses are a great issue of concern as they can cause billions of dollars’ worth harm to the economy each year.

Since the computer virus only hits the programming of the device, it is not visible. But there are certain indications which can help you analyse that a device is virus-hit. Given below are such signs which may help you identify computer viruses:

Speed of the System – In case a virus is completely executed into your device, the time taken to open applications may become longer and the entire system processing may start working slowly
Pop-up Windows – One may start getting too many pop up windows on their screen which may be virus affected and harm the device even more
Self Execution of Programs – Files or applications may start opening in the background of the system by themselves and you may not even know about them
Log out from Accounts – In case of a virus attack, the probability of accounts getting hacked increase and password protected sites may also get hacked and you might get logged out from all of them
Crashing of the Device – In most cases, if the virus spreads in maximum files and programs, there are chances that the entire device may crash and stop working

The first thing which you might notice in case of virus attack is the speed with which your system shall process. And then gradually other changes can also be observed.

Difference between Malware and Virus

Malware	Virus
Definition: Malware is a software which is designed to get unauthorised access of a computer system, generally for a third party benefit.	Definition: A virus is a code which attaches itself to various files and programs which get infected in a manner that they can disrupt and corrupt a device.
Types of Malware include: Virus Trojan Worm Ransomware Spyware Adware	Types of Virus include: Boot sector Multipartite Spacefiller Resident Polymorphic File infector Direct Action Macro
The full form of Malware is Malicious Software	The full form of Virus is Vital Information Resource Under Seize
A computer system with a malware software can be repaired using an antimalware software	Antivirus is used to remove viruses from a computer device
If a malware software affects your computer device, it may: Try to retrieve personal information Steal data like saved cards or payment details Initiate mining for bitcoin Overpower its presence and execute unwanted tasks	A system attacked by a computer virus can be apprehended if: The processing speed decreases Too many pop-ups appear on the screen Passwords are reset Different programs begin to execute themselves
Examples of Anti-Malware software include: Total AV Bitdefender Malwarebytes Hitman Pro	Examples of Antivirus software are: McAfee Norton Avast Kaspersky

10) OUTPUT DEVICES

Output devices return processed data that is information, back to the user. Some of the commonly used output devices are:

1. Monitor (Visual Display Unit)

2. Printers

3. Speakers

1. Monitor

Out of all the output devices, monitor is perhaps the most important output device because people interact with this device most intensively than others. Computer information is displayed, visually with a video adapter card and monitor. Information processed within the CPU, that needs to be visually displayed, is sent to video adapter. The video adapter converts information from the format used, in the same manner as a television displays information sent to it by a cable service.

TYPE OF MONITOR

LCD

Liquid Crystal Displays (LCD): This type of monitors are also known as flat panel monitor. Most of these employ liquid crystal displays (LCDs) to render images. These days LCD monitor are very popular.

When people talk about the capabilities of various monitors, one critical statistic is the resolution of the monitor. Most monitors have a resolution of at least 800 x 600 pixels. High-end monitors can have resolutions of 1024 x 768 pixels or even 1280 x 1024 pixels. Thus monitors are available either in low resolution or in high resolution

LED

Short for light-emitting diode monitor, an LED monitor or LED display is a flat screen, flat-panel computer monitor or television. It has a very short depth and is light in terms of weight. The actual difference between this and a typical LCD (liquid-crystal display) monitor is the backlighting. The first LCD monitors used CCFL (cold cathode fluorescent lighting) instead of LEDs (light-emitting diodes) to illuminate the screen.

LED monitor advantages

LED monitors offer many benefits compared to those that are CCFL backlit including:

· Often less expensive.

· Broader dimming range.

· Overall more reliable.

2. Printer

After a document is created on the computer, it can be sent to a printer for a hard copy (printout). Some printers offer special features such as colored and large page formats. Some of the most commonly used printers are:

1. Laser Printer

2. Ink Jet Printer

3. Dot Matrix Printer

Laser Printer: A laser printer produces high quality print that one normally finds in publishing. It is extremely fast and quiet. Moreover, the operation of a laser printer is easy with automatic paper loading and no smudging or messing up of ink ribbons. The fastest laser printer can print up to 200 pages per minute in monochrome (black and white) and up to 100 pages per minute in colour.

Ink-Jet Printer: An ink-jet printer creates an image directly on paper by spraying ink through as many as 64 tiny nozzles. Although the image it produces is not generally quite as sharp as the output of a laser printer, the quality of ink-jet images is still high.

In general, ink-jet printer offers an excellent middle ground between dot matrix and laser printer. Like laser printer, an ink-jet printer is quiet and convenient, but not particularly fast.

Typically, an ink-jet printer is more expensive than a dot-matrix printer, but costs only half as much as a laser printer.

Dot Matrix Printer: The dot matrix printer was very popular at one point of time. It is a very versatile and inexpensive output device. In dot matrix printer the print head physically "hits" the paper through the ribbon and produces text (or images) by combinations of dots; hence the name dot matrix printer. Its speed is measured in characters per second (CPS). Although it is less expensive, it is louder, slower and produces lower print quality.

3. Speaker

Speakers are another type of output device, which allow you to listen to voice like music, and conversation with people.

BASIC OF COMPUTER FUNDAMENTAL BY AKSHAY SHELKE (NEVER WIN..!)

2) Computer Hardware