A desktop computer is a multipurpose device. It has various components which includes:
1. Monitor: a computer monitor is an output device which enables the user to visualize the things and thus provides the ability to the user to interact with the computer in a systematic manner. They have evolved from CRTs(Cathode Ray Tubes) from the late 70s which produced monochromatic images of low quality to the present day OLEDs which provide a better quality image and also consumes less power.
The monitors use picture elements called pixels. These pixels are present all over the screen. Each pixel has its own RGB value which can be set to give it different colors . These individual pixels then collectively form an image. Modern day computers can have as much as (normally) 1024×768 pixels.
2.cpu:CPU(Central Processing Unit) ,a microprocessor, is the brain of the computer. It is a chips consisting of millions of transistors. All the basic functions like the arithmetic, control, input-output and logical operations of the computer is performed in the CPU. Over time CPUs have evolve to become smaller and faster.
The CPU is not just a discrete unit but is an assembly of various parts: These parts include:
a.RAM: RAM, or Random Access Memory, as the name suggests, is the volatile memory of the system. This thus allows the user to read or write the data items at the same time regardless of the data’s physical memory location. The computer uses RAM as loading data in the RAM takes very less time when compared to the time taken to run the same data in a hard drive. Desktops usually have two RAM ports with which the user can increase the size of the RAM to the desired value by just putting another RAM in the slot provided.
RAM are further of two types:
i. DRAM (Dynamic Random-Access Memory)
ii. SRAM (Static Random-Access Memory)
b. Motherboard: The Motherboard is the main PCB(Printed Circuit Board). It is basically the nervous system of the computer. It allows communication between the components of the system(CPU, RAM, and other hardware components). It is responsible for the regulation of power received by the CPU, hard drive, and the other components.
Modern Motherboard consists of :
i. Power connectors(distributes power),
ii. Clock generator(generates clock signals),
iii. Sockets(for the installation of microprocessors),
iv. Connectors for Hard drives , etc.
c. Hard drives: Hard disk drive(or HDD) is the main storage of the computer. It stores all our information present in the computer ranging from our personal pictures to our college assignment. It stores data in a rotating magnetic (coated with a magnetic material) disk. There was a time when a hard drive of 3 Mb would cost you lakhs of rupees but now even a 1 Tb hard drive just costs 3 thousand rupees. Hard drives have a motor which makes the disk rotate. Modern day hard disks can rotate up to 10000 rpm can transfer data at the rates as fast as 1 Gbits per second. These days external hard disks are also available which makes these drives very portable. The hard disks are now getting replaced with SSDs(solid state drives) which are a bit costlier then hard drives but offers a faster data transfer rates when compared to the rates offered by HDD.
d. Bus: The CPU transfers data to its various components or to another computer using the interconnected pathways called buses. These buses are electrical wires with bit serial and parallel connectors. Additional components such as TV card, sound card, etc. can also be connected to the computer using the expansion bus.
Buses have the following function:
i. Data Sharing( between the connected computer peripherals)
ii. Supplies Power( to various computer peripherals)
iii. Synchronizes peripherals( by providing a system clock)
iv. Addressing( directs data to the desired memory location)
Majorly buses are divided into two types :
I. System Bus( Connects CPU and the main memory)
II. I/O Buses: ( Connects CPU to various phripheral)
3.mouse: a computer mouse is a handheld input device. The user holds the mouse to guide the mouse cursor, thus allowing him to navigate through the whole screen.
4.keyboard: keyboard is an input device. It has keys with letters( also symbols) engraved on it which can be used to type text and numbers into a word file or any other program. A combination of keys can also be used to give certain commands to the system e.g. Ctrl+C and Ctrl+V are used for Copying and Pasting respectively. Different types of Keyboards are available in the market. Four major keyboards which are used worldwide are QWERTY, QWERTZ, AZERTY and HCESAR, out of which QWERTY is the most widely used.