Fundamental of computer
Introduction to Computer
A computer is an electronic device that takes data as input, processes it according to the given instructions and delivers output in human understandable form with the ability to also store data for future use.
Characteristics of Computers:
- Speed: Computers are much faster than humans, capable of performing millions of tasks per second, saving a great amount of time.
- Accuracy: A computer is 100% accurate if the input and instructions provided to it are accurate. The only time an error occurs is when there is a GIGO (Garbage In Garbage Out) situation.
- Diligence: Diligence means the computer is capable of doing any form of work for a long period of time without getting tired and getting bored.
- Reliability: Reliability means that the results the computer produces are trustworthy and correct. It is the most important thing one needs to use the data, i.e. to know if it is accurate or not.
- Versatility: Versatility means that the computer is capable of doing any type of work, and in every field/sector. Today computers are used in almost everywhere like school, house, office, hospitals, etc.
- Storage: Computers have a great amount of storage capacity that can store any type of data and information such as files, photos, audio and video, etc. for future use.
- Multitasking: A computer can perform multiple tasks at the same time without compromising its efficiency and accuracy and this can save a lot of time for the user.
- No Feeling: A computer is a feeling and emotionless machine that just does what it is instructed to do. Although humans have developed robots that can react, the reactions they give are all programmed through various algorithms and programs.
Application Area of computer:
- Education: Computers are important for online classes, download study materials from the internet and interact with fellow learners. Computers are also used to track student attendance and learning.
Banking: Computer helps to store the data of the users (account holders) on the bank server. All the transactions are stored and maintained through these computers.
- Government Sector: The government can easily monitor the government sector and all the data necessary with the help of computers. It can keep a record of all the necessary documents in the computer.
- Defense System: Computers are used by the military to track different activities that can hamper the security of the nation. Features like GPS Tracking, Remote access can be used with the help of a computer.
- Research: Computers are used for research purposes to do experiments virtually and know more about different kinds of things. It helps to keep track record of that research and share the result to people all around the globe.
- Entertainment: This is the most popular application area of computers as computers are widely used for entertainment purposes for example to play games, watch movies, listen to music and so much more.
- Communication: Computers are used for communicating with people far from us with the help of the internet. Computers have made exchange of photos and videos easier and faster and with just a simple click anything can be shared to anyplace in the world.
Generation of Computer System:
The modern computer took its shape with various changes, big and small, obviously for its betterment in terms of speed, accuracy, size, architecture, processor and many more. This moment of change over time is called generation of computer systems.
1. First Generation Computer:
-1940s-1950s
-Used vacuum tube as main electronic component
-were slow, heavy and large
-machine language was used as programming language
-produced too much heat
- IBM 650, IBM 701
2. Second Generation Computer:
-1950s-1960s
-Used Transistor as main electronic component
-were faster and small in comparison to 1st generation computer
-machine language & assembly language was used as programming language
-produced less heat
-IBM 7090 & 7094
3. Third Generation Computer:
-1960s-1970s
-Used IC (Integrated Circuit) as main electronic component
- High level language was used as Programming Language
-IBM 360, IBM 370
4. Fourth Generation Computer:
-1970s-Present
-Use Microprocessor as main electronic component
-are small and portable
-IBM PC, Apple Macintosh
5. Fifth Generation Computer:
-Present - Future
-Used Artificial Intelligence as main electronic component
- understand natural language
-are small and portable
-Laptops, tablets, smartphones
Types of computer (On the basis of Working Principal):
1. Analog Computer:
Analog computers are those computers that process analog data and are used to measure natural & physical values like voltage, electric current, etc. It is used for specific tasks only. Analog data are continuous data that varies continuously and cannot have discrete value. Such computers are used for scientific, engineering, and research applications. Speedometer, thermometer, etc are some of the examples of analog computers. These types of computers give the output in the form of curved lines and graphs.
Features:
a. It is used for specific tasks.
b. It processes analog data.
c. It is high speed as it works on real time data (continuous data).
2. Digital Computer:
Digital computers are those computers that process data in terms of 0s and 1s. They are multi-purpose computers with high capacity and adaptability. The digital computers have high accuracy and higher storage capacity. Even if they have high processing speed, they are slower in operation than analog computers and are cheaper too. Digital computers have high storage capacity and are reprogrammable as per the users' needs. Eg: IBM, IBM Compatible, etc.
Features:
a. It processes data in terms of 0s and 1s.
b. They are multi-purpose computers.
c. They have high accuracy and storage capacity.
3. Hybrid Computer:
Hybrid computers have both the features of Analog as well as Digital computers. It is fast like the analog computer with the accuracy of a digital computer. It can process both continuous and discrete data. It takes analog signals and transforms them as digital form before processing them.
Features:
a. It has the features of both analog and digital computers.
b. High speed and high accuracy.
c. Processes both continuous and discrete data.
Basic Organization of Computer
The function of computers are: Input, Process, Output and Storage
- Input Unit:
The devices that are used to give data and instructions to the computer are called input units. It converts the user input into binary signals so that the computer can understand it. Some of the common input devices are : Keyboard, Mouse, Scanner and Microphones.
- Processor:
The processor is responsible for all the arithmetical and logical operations. It is the core of the computer that does all the calculation and solving. The processor is divided into two parts:
- ALU (Arithmetic Logical Unit):
- The ALU performs arithmetic operations (addition, subtraction, multiply, division).
-It handles logical operations (comparing and decision making).
-Supports AI and Machine learning in modern computers.
- CU (Control Unit):
The control unit is the decoder of the computer and acts like a monitor that look after all the components of the computer.
- Directs the operation of all the computer components.
- Decodes the instructions and coordinates the flow of data.
- Sends control signals to memory and Input Output devices.
- Register:
Registers are the fastest memory that is located inside the CPU itself. It is a temporary memory that is responsible to hold the data and instructions of the program that is currently being executed. The more the register, the faster the computer becomes.
- Fastest memory
-Located inside the CPU
- Memory Unit:
The memory unit holds the data and instructions before, during and after the processing happens. There are two types of memory units. They are:
- Primary Memory:
The primary memory also known as main memory is used to store the data, instruction and immediate result of programs that are currently being executed. The primary memory is further classified into two types:
i) RAM (Random Access Memory): RAM stands for “Random Access Memory”. The RAM is a type of computer memory that stores data temporarily that means it is volatile. When the computer is closed the data is lost. RAM helps the computer to run programs and process information faster. The RAM is of 2 types: DRAM (Dynamic Random Access Memory), SRAM (Static Random Access Memory).
ii) ROM (Read Only Memory): ROM stands for “Read Only Memory”. This is a non-volatile memory. It is designed to save essential data and information permanently. That means even if the computer is closed the data is still there. ROM is cheaper in cost as compared to RAM. The ROM is of three types: PROM (Programmable Read Only Memory), EPROM (Erasable Programmable Read Only Memory), EEPROM (Electrically Erasable Programmable Read Only Memory).
- Secondary Memory:
Secondary memory, also known as secondary storage, are those devices that are used to store data and information even when the computer is turned off. Secondary memory is slower than Primary memory (RAM) but has more storage capacity. They are portable, which means you can take your data and information anywhere you want and transfer it to other devices. Secondary Memory can be used for backup and restore purposes. Some examples of Secondary memory are: Hard Disk Drive (HDD), Pen Drive, CD/DVD Drive, etc.
Computer Software
Software is a collection of programs, data, and instructions that tell a computer how to work and perform specific tasks. Software is not a physical thing like hardware and is used to give instructions to the hardware.
A program is a set of instructions written in a programming language that a computer can execute to perform a specific task.
Hardware is the physical parts of a computer system that you can see and touch, such as the CPU, monitor, keyboard, mouse, and storage devices.
Types of software:
1. System Software:
System software is a type of computer software designed to manage and control the hardware components of a computer, and to provide a platform for running application software. In simple terms, it acts as a bridge between the hardware and the user. It is further classified into three types:
a. Operating System (OS)
- Acts as an interface between hardware and users.
- Manages CPU, memory, files, and input/output devices.
- Provides user interfaces (command-line or graphical).
- Examples: Windows, Linux, macOS.
b. Translating Program
- Convert high-level programming languages into machine language.
- Types: Compiler (translates whole code),
Interpreter (line by line),
Assembler (for assembly language)
- Make it possible for computers to execute user-written programs.
c. Utility Software
- Supports system maintenance and performance improvement.
- Includes antivirus, file compression tools, disk cleanup, and backup software.
- Works alongside the OS but focuses on optimization and security.
2. Application Software:
Application software is a type of computer program that allows users to perform specific tasks on a computer or mobile device. Application software always depends on system software, especially the operating system, to function properly. Common examples include Microsoft Office, Google Chrome, Photoshop, and WhatsApp.
It is of two types they are:
a. Tailored (Custom/Generic) Software
- Developed specifically for one organization’s needs.
- Flexible and can be modified as requirements change.
- More expensive and time-consuming to develop.
- Provides higher efficiency for specialized tasks.
- Example: Software for a hospital or bank management system.
b. Packaged Software
- Designed for general use by a wide range of users.
- Ready-made and available off the shelf.
- Cheaper and quicker to obtain.
- May include features not needed by all users.
- Example: MS Office, Adobe Photoshop, Tally.
Accessories and Data Handling
Input Devices:
An input device is a hardware component used to enter data and instructions into a computer for processing.
Peripheral devices:
Peripheral devices are external hardware devices connected to a computer to add functionality, such as input, output, or storage. Examples include printers, scanners, external hard drives, and keyboards.
Input Devices:
a. Keyboard
- Used to input text, numbers, and commands into a computer.
- Consists of keys such as letters, numbers, function keys, and special keys.
- Connects via USB, Bluetooth, or PS/2 port.
- Most common and versatile input device for data entry.
- Examples: Standard QWERTY keyboard, ergonomic keyboard.
b. Mouse
- A pointing device used to interact with graphical elements on the screen.
- Moves the cursor and selects, drags, or clicks on objects.
- Can be mechanical (ball) or optical (laser).
- Connects via USB, Bluetooth, or wireless dongle.
- Examples: Optical mouse, wireless mouse, trackball.
c. Scanner
- Converts physical documents or images into digital format.
- Can read text, pictures, or barcodes for computer use.
- Types include flatbed, sheet-fed, and handheld scanners.
- Connects via USB or network to send data to the computer.
- Examples: Flatbed scanner, barcode scanner.
d. Microphone
- Captures sound and converts it into digital data for the computer.
- Used for voice recording, video calls, and speech recognition.
- Can be built-in, USB, or wireless.
- Requires software or drivers to process the audio input.
- Examples: USB microphone, headset mic, condenser mic.