What Is Computer ?

A computer is a programmable electronic device that accepts raw data as input and processes it with a set of instructions (programs) to produce results as output. It presents the output after performing mathematical and logical operations and can save the output for future use.

A computer is designed to execute applications and provide a wide variety of solutions through integrated hardware and software components. It works with the help of programs and represents a decimal number through a string of binary digits. It also has a memory that stores data, programs and processing results. The components of a computer such as machinery that includes wires, transistors, circuits, hard disks are called hardware.

A computer is a machine that can be instructed through computer programming to automatically complete a sequence of arithmetic or logical operations.It can process numerical as well as non-numerical calculations. The word “computer” is derived from the Latin word “compute” which means to compute.

Depending on the size, a computer can be divided into five types:

  • Micro Computer
  • Mini Computer
  • Mainframe Computer
  • Super Computer
  • Workstations

The basic parts without which the computer cannot function are as follows:

  • Processor
  • Memory
  • Motherboard
  • Storage Device
  • Input Device
  • Output Device


A computer processor is a microchip that is embedded in the motherboard of the computer and controls all the components connected to the computer. It takes data as input and processes it thousands of millions of times faster and gives us results as output with the help of output devices. The processor is a multi-programmable logical device. The processor requires information for processing data. And it gets this information from memory like RAM.We use cache (Cache) memory to reduce the time it takes to process data from memory. The latest microprocessor is known as Level 1 (L1) cache. The microprocessor keeps the required information stored in the cache. The microprocessor first checks that information in cache memory if the microprocessor finds the required information in the cache. So this is known as Cache Hit and if the microprocessor does not find the required information, it is known as Cache Miss and the processor searches for the information given in RAM.


This memory is like our brain which is able to store and remember previous functions. Similarly, term memory in a computer represents a chip that stores data. This enables us to retrieve the stored data. It retrieves the data and instructions stored in memory for processing the data. Memory storage capacity depends on the type of memory package. Data and instructions entered into the computer system by input units are stored in the computer by some storage media. This storage media is known as memory.
Memory is an important function of a computer where all data and information are stored as binary digits (0 and 1). Memory is a computer system that is required for post-retrieval processing of data and instructions. The computer system uses various devices to store instructions and data. What is needed for its operation is that generally we classify a computer into two basic categories (Categories). Data and instruction memory have two main functions: to store programs, data and information in a computer, the results of computation. Memory is required to store.


It is a printed circuit board where all the parts of a computer system are connected. Central processing units (CPUs), memory (RAM), hard drives, and every part of a system are connected to the motherboard via sockets, slots, and connectors. Typically, a motherboard chipset (Chipset) ), Controls the features and capabilities of the motherboard. The motherboard chipset is a series in which the motherboard is part. The chipset is very important for the operation of the system.

Storage Device

The hard disk is a secondary and permanent data storage device. It is similar to the human brain where all the past and present events are stored. It is made up of Magnetic Material which follows and stores the data.
A hard disk is a storage device, which we use to store our data. Permanently stores hard disk data. The first hard disk was created by an IBM company with a storage capacity of just 5 MB and weighing around 250 KG. Later, many changes were made, resulting in today’s modern Hard Disk. It consists of a circular disk on which digitally save data, which rotates very fast, the speed of which we measure in RPM (Revolutions Per Minute), obviously the higher the RPM, the higher the data read and write speed.

Input Devices

An input device can be defined as an electro mechanical device that helps a user input data into a computer, such as keystrokes on a keyboard and clicking with a mouse, we input data into the computer. The data is entered into the main memory through the input device. They accept the instruction from the user and convert the accepted instruction into machine language. The following are examples of some input devices:
Keyboard: It is an input device that allows the user to input alphabets, numbers and other characters. It is a board with a set of buttons by which pressing a set of keyboard buttons is a primary device for inputting data into a computer.
Trackball: A trackball is a rotatable ball on a permanent device, which is manually rotated using the fingers. It is also a pointing device. They are used in playing video games.
Joystick : A joystick is an input device which is a vertical stick shaped device with the help of which we move the cursor in any direction. There is usually a button at the top of it which is used to select the option indicated by the cursor. The joystick is primarily used as an input device used to control video games, training simulators, and robots.
Light Pen: It is an electro-optical pointing device, which is used for drawing, graphics and menu selection. The pen has a photocell in a small tube. It senses the light through a photocell attached to it and when it comes close to the screen it generates a Pulse. It is used exclusively in Personal Digital Assistants (PDA). Very useful in identifying a specific location. However, it does not provide any information on any blank part of the screen.
Barcode Reader: A barcode reader used to input data from a barcode. Shops and malls have barcodes on most products. Barcode reader detects the existing data in the barcode by hitting a beam of light on the barcode lines.
Graphics Tablet: A graphics tablet is a computer input device that allows images and graphics to be used by hand, drawing the picture with a pencil and paper, in the same way that a graphics tablet allows that picture And graphics are taken into the computer as input. These devices are used to obtain data from handwritten signatures. Some tablets are used as navigation tools like a mouse. They are used by architects, engineers and designers in Computer Aided Design (CAD) for design purposes, such as buildings, cars, mechanical parts, robots, etc. They are also used in the digitization of maps i.e. Global Positioning System (GPS).

Output Devices

The output device is a core part of computer hardware, when the input we give to the computer through the input device is the result we get after processing the data, the result we get from the output device itself. The most computer data output for humans is in the form of audio or video. Thus, most of the output devices used by humans are in these categories. Examples include monitors, projectors, speakers, headphones, and printers. We can print the output by looking at the computer monitor, listening through the speaker, through the printer. Examples of some output devices are the following: Monitor (monitor): A monitor is an output device similar to a TV screen and uses a Cathode Ray Tube (CRT) to display information. The monitor is manually connected to the CPU and displays information as we know it also displays program or application output. Like television, monitors are also available in different sizes. Liquid Crystal Display (LCD): LCD was introduced in the 1970s and. Due to its low energy consumption and small and light size, it was also used in portable computers (laptops). Light Emitted Diode (LED) is an electronic device that emits light, which produces light when an electric current passes through it. LEDs typically produce red light, but today’s LEDs can produce RGB (red, green, and blue) light, as well as white light. Thin Film Transistor (TFT) and Active Matrix LCD (AMLCD) is a liquid crystal display (LCD) with active matrix display, each pixel is controlled by one to four transistors that can make the screen brighter, more bright. Colorful and viewable at different angles. Because of this technology, the Active Matrix Screen is often more expensive but has a better quality than the Passive Matrix Display. Printer: The printer is primarily used to convert softcopy to hardcopy. Depending on the technology used, they are classified as Impact or Non-Impact Printer. Impact printers use a typewriting printing mechanism in which a hammer strikes the paper through a ribbon to produce output. Dot matrix printers fall into this category. Non-impact printers do not touch the paper while printing the paper. They use chemical, heat, or electrical signals to bring symbols to paper. Inkjet Printer, Deskjet Printer, Laser Printer, Thermal Printer fall into this category. Plotter (plotter): This is an output device that uses a pen, pencil, marker, or other writing tool to create vector graphics. Just like the printers we use to print documents or images, the plotter uses large images in size to print on paper, they are mainly large images or images such as construction plans, mechanical objects, AUTOCAD, Used to produce blueprints for CAD / CAM, etc. Plotters generally come in two designs: Flat Bed Plotter It is small in size and can be easily worked by placing it on the table, but it has limited paper length so that they are given a smaller size It can be used easily at home and office. Drum Plotter It uses an unlimited length of paper rolls and is very large in size. Speaker (speaker): This is an output device that receives sound in the form of an electric current. It requires a sound card connected to a CPU, which produces sound through a card. These are used to listen to music. Headphones (headphones): This is a pair of small loudspeakers that are normally used by a user. Is held near the ear and connected to a source such as a music player, radio, CD player or portable media player. They are also known as Stereophone or Headset. Projector (projector): It is an output device that is used to display information from a computer to a large screen, so it is used to convey information to a large group of people Widely used to demonstrate large audience groups as well as used in classroom training or conferences This is a temporary output Provides display.