The Ultimate Guide on the Hardware and Software/components of the computer

Knowing the hardware of the computer is very important as an IT engineer and this tutorial gives you each and every information about the same. In this tutorial learn everything about the Hardware and Software/components of the computer.

What is Computer System?

The computer contains mainly two parts: Hardware and software.The computer is a programmable electronic device that can be programmed to accept the input and then provide the output. The Computer hardware can only understand binary numbers that are 0 or 1. Computer transfer data one byte at a time.

Computer stores all data on the hard disk as 0 or 1 Binary numbers. ASCII ( American Standard Code for information interchange.

What are Computer hardware’s?

Hardware is made up of various electronic circuits and components such as I/O devices, CPU, disk, and the motherboard.

  • Input Devices: The input device is used to provide the input ( data, instructions) into the RAM of the computer such as
    • Keyboard
    • Trackball ( the upper part of the mouse)
    • light pen
    • OBR (Optical Bar Code reader) – This is used to scan the vertical bars, read tags.
    • OCR ( Optical Character reader) – This is used to detect the alphanumeric characters like reading passanger tickets, computer printed bills of credit card.
  • Output Devices: The output devices provides the end result which user provided as input such as monitor.
    • Monitor also known as VDU ( Visual display unit). It contains CRT ( Cathode ray Tube) which displays the character as output.
    • Ther are many different types monitors available in market such as CGA ( Color graphics adapter) , EGA (Enhanced graphic adapter) ,VGA ( Video graphics adapter), SVGA (Super VGA) which is best in market.
  • CPU( Central Processing Unit): CPU is the most important hardware part of the Computer which performs all the functions and execution of input data. It executes the instructions stored in the main memory. CPU has a set of electronic circuits that executes the program instructions. CPU contains its own memory that is Cache to immediately process the data,
  • Memory or storage: This a a storage place where all the data resides. Again there are two categories in memory i.e Primary and the secondary memory.
    • Primary memory: These memory are directly connected with CPU and are extremely fast such as RAM (Random Access Memories) which is volatile in nature and ROM (Read Only Memories) that is non volatile in nature. The CPU works with these memory only.
    • Secondary Memory: These memory are not directly connected to the CPU such as Floppy disk, CD Rom ,hard disks or RAM.
  • Motherboard: The motherboard is most important hardware component like a circuit board. It is the main printed circuit board ( PCB ) found in computers. CPU is installed in one of the sockets of the motherboard or directly soldered. There are slots in which memory is installed.
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  • Buses: The data is stored in 0 or 1 binary format in register in a form of a unit. When the data needs to travel or move from one registers to other then you need a seperate wires and these wires are known as buses.
    • The data bus is used to move data,
    • Address bus to move address or memory location
    • Control bus to send control signals between various components of a computer.
  • Types of Buses
    • System bus transfers information between different parts inside computer system.
    • Control bus has two wires, set and enable. When CPU wants to read from RAM, the enable wire will be opened; when CPU wants to save information on RAM, CPU will enable the set wire.
    • Data bus is a two-way bus carry data commute between CPU and RAM.
    • Address bus is a one-way bus carry addresses from CPU to RAM.
  • Clock: Clock is an important component of CPU which measures and allocates fixed slot for processing each and every micro operations.
    • The clock speed measures the number of cycles your CPU executes per second, measured in GHz (gigahertz).
    • A CPU with a clock speed of 3.2 GHz executes 3.2 billion cycles per second
    • The CPU is allocated one or more clock cycle to complete the micro operations.
    • The processor base frequency refers to the CPU’s regular operating point, while the Max Turbo Frequency refers to the maximum speed the processor
    • The CPU executes the instructions in synchronization with the clock pulse.
    • The operations are performed with a speed of clock cycle per second (MHz) with a range of 4.77 MHz to 266 Mhz.
    • The speed of CPU is measured in terms of MIPS( Millions of instructions per second) or cycles per second
    • Each central processing unit has an internal clock that produces pulses at a fixed rate to synchronize all computer operations

Chipsets: Chipset handles an incredible amount of data. It is the glue that connects the microprocessor with the motherboard. It contains two basic parts northbridge (connects directly to processor via FSB i.e front side bus) and the South Bridge primarily handles the routing of traffic between the various input/output (I/O) devices on the system for which speed is not vital to the total performance, such as the disk drives (including RAID drive arrays), optical drives.

Video (Graphics) Card:

A dedicated video card (or video adapter) is an expansion card installed inside your system unit to translate binary data received from the CPU or GPU into the images you view on your monitor. It is an alternative to the integrated graphics chip.
Modern video cards include ports allowing you to connect to different video equipment; also they contain their own RAM, called video memory. Video cards also come with their own processors or GPUs

Sound Cards

  1. Sound cards attached to the motherboard and enabled your computer to record and reproduce sounds.
  2. Most computers ship with a basic sound card, most often a 3D sound card. 3D sound is better than stereo sound

Ethernet Card/Network Cards

An Ethernet network requires that you install or attach network adapters to each computer or peripheral you want to connect to the network. Most computers come with Ethernet adapters preinstalled as network interface cards (NICs).

CPU (Central Processing Unit)

CPU is the most important hardware part of the Computer which performs all the functions and execution of input data. It executes the instructions stored in the main memory. CPU has a set of electronic circuits that executes the program instructions.

An example of a CPU is Intel 8085 which was an 8-bit microprocessor.

The U is for Ultrabook: Intel's low-power, dual-core Haswell CPUs unveiled  | Ars Technica
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Computer interacts with primary storage that is the main memory for processing data and instructions. CPU contains mainly two components Arthematic Logic Unit and Control Unit.

  • Arthematic Logic Unit (ALU) is a digital circuit that performs all the calculations such as bitwise and mathematical operations on binary number.
  • Control Unit: CU controls all the activities such as transfer of data, instructions. It takes or obtains the instructions from the memory and understands it and then forward it further for execution or calculations. The control unit sends the control signals along the control bus.
  • Registers:  These are high speed memory built into CPU chip circuits to acess or store the data immediate from the calculations or instructions performed by ALU. They act as high speed temporary memory. Registers can store two words at a time until overwritten. CPU needs to process very fast so in order for CPU to process the instructions or data from the RAM you need a place high memories in between which is Registers.
    • Registers work under the direction of the control unit to accept, hold, and transfer instructions or data and perform arithmetic or logical comparisons at high speed.
  • Types of Registers
    • Program Counter: Stores the address of next instruction to be executed
    • Accumulator: This registers temporarily stores data from ALU immediately.
    • Memory Address Registers: Stores the address of current instruction being executed
    • Memory data Registers or Memory Buffer Registers: Holds the data from that is copied from the RAM and ready for CPU to process
  • Below is the Image snapshot of various registers that are used in the CPU.
  • Cache (L2 or L3). A processor uses memory installed in the chip itself to store and speed up operations before utilizing external system RAM. This on-board memory is stored in one or more caches, which are identified L2 or L3. More powerful processors will be equipped with larger caches.
  • Socket Unit: On which CPU is installed on the motherboard.

Computer Architecture and its Working

The Working a Computer system comprises input operations, storage operations, data processing, and output operations.

  1. When you press a key on your keyboard lets say ABC. The keyboard has PCB behind it which converts the alphabets ABC into the binary number and sends it to the CPU.
  2. The other scenerio could be execution of a single program like 35 + 49
  3. CPU component that is Control unit fetches (gets) the instruction from the RAM memory how to draw ABC ( basically like opcode, operand) using the data bus and also in the mean time asks RAM to store this in your memory until I perform execution of calculation. ( At times CPU fetches from Hard disk instead of RAM as your OS lies in the Hard disk)
  4. Data bus brings the data and instructions in CPU’s internal memory that is registers for processing the data.
  5. The control unit decodes the instruction (decides what it means) to machine bianry code and directs that the necessary data be moved from memory to the arithmetic/logic unit. The steps (2,3,4)together are called instruction time, or I-time.
  6. The arithmetic/logic unit executes the arithmetic or logical instruction. That is, the ALU is given control and performs the actual operation on the data.
  7. Thc arithmetic/logic unit stores the result of this operation in memory or in a register. ( Step 5 and 6 are Execution or E time)
  8. The control unit eventually directs memory to release the result to an output device or a secondary storage device. The combination of I-time and E-time is called the machine cycle. To Perform all the instructions it is known as clock cycles that is executes 5 instructions and nowadays Modern CPU’s can perform millions of clock cycle per second.
  9. All these things are happening on the circuit known as motherboard.
Step by Step function of CPU along with Memory

Another example of how a computer works

  • Suppose your Hard disk has 500 processes.
  • Suppose RAM can execute a maximum of 50 process.
  • Lets say: You ran a program which is an executable code (low level code that is machine code) to run 500 process that are stored in the hard disk.
  • Then as CPU will request RAM to provide the 50 process instructions to execute. If in case it doesnt have then it asks Hard disk to provide the instructions.
  • Harddisk copy the instructions to RAM and then CPU fetches from the RAM.
  • For Hard disk to copy 50 Process to RAM and then CPU to fetch from RAM is decided by Operating system using different algorithms such as short term scheduler or long term scheduler.

Data flow from CPU to Memory and Vice Versa

Step by Step function of CPU
  1. The MAR stands for Memory address register which is connected to the Address Bus. It stores the memory address of an instruction. The sole function of MAR is to contain the RAM address of the instruction the CPU wants.
  2. The MDR stands for Memory data register which is connected to the Data Bus. It holds the data that will be written to the RAM or read from the RAM. Even when ALU performs the operations the data is stored in high memory registers such as MBR or MDR
  3. The relationship between MAR and MDR is that the MAR gives the address the data of the MDR will be read from or written to.
  • .

Single Core CPU v/s Multi Core CPU

Single-core CPU will only be able to process one program at a time. However, when you run multiple programs simultaneously, then a single-core processor will divide all programs into small pieces and concurrently execute with time slicing.

For EX:

P1 initiated——————————————————– P1 Ends

P2 initiated ——————————— P2 Ends

P3 Initaited —————- P3 Ends

Unlike single-core processing, it is a way in which computing tasks are divided into sub-parts, and a multicore processor (multiple CPU cores) execute each sub-task simultaneously.A dual-core CPU literally has two central processing units on the CPU chip. A quad-core CPU has four central processing units, an octa-core CPU has eight central processing units, and so on.

P1 initiated—————— P1 Ends

P2 initiated —————– P2 Ends

P3 Initaited —————– P3 Ends

Hyper Threading or Logical Processor or Threads of CPU

Threads are the virtual components or codes, which divide the physical core of a CPU into virtual multiple cores. A single CPU core can have up to 2 threads per core. For dual-core (i.e., 2 cores) it will have 4 threads, for Octal core (i.e., 8 core) it will have 16 threads, and vice-versa.

Windows’ Task Manager shows this fairly well. Here, for example, you can see that this system has one actual CPU (socket) and four cores. Hyperthreading makes each core look like two CPUs to the operating system, so it shows 8 logical processors.

Threads of Processes

The thread is created by a process. Every time you open an application, it itself creates a thread that will handle all the tasks of that specific application. Like-wise the more application you open more threads will be created.

The threads are always created by the operating system for performing a task of a specific application.

Batch Processing vs Multi programming vs vs Multiprocessing vs Multitasking vs Multithreading Operating Systems

Batch processing is the grouping of several same processing jobs to be executed one after another by a computer without any user interaction.

Multiprogramming is the ability of an OS to execute multiple programs at the same time on a single processor machine.

Multiprocessing system: When one system is connected to more than one processor which collectively works for the completion of the task.

Multithreading is a conceptual programming paradigm where a process is divided into a number of sub-processes called threads. Each thread is independent and has its own path of execution with enabled inter-thread communication.

Magnetic Storage Device

There are devices that are known to be magnetic storage devices as they have a layer of magnetic substance on their surface. These devices have a read-write assembly that converts data and instructions in the form of 0 or 1 into some form of the magnetic signal.

Floppy: The floppy disk stores the data in the form of a magnetic signal and while data is stored they are converted from 0,1 to magnetic signals. These were introduced by IBM and later were known as diskettes. They have an option called a small sliding switch called write-protect notch from which you cannot delete the data from the floppy drive.

Hard Disk: Can store a huge amount of data and have hard platters that hold magnetic medium compared to floppy disks compared to floppy and tapes that have plastic films. Information remains intact even after switching off the computer. So in computers, Operating System is installed and stored on the hard disk. As the hard disk is non volatile memory, OS does not lose on the turn off

Magnetic tapes: They are similar to tapes that you see in cassettes or video cassettes and are divided into tracks. One of the tracks is used to detect the error. They can store as much as 10GB of data. It allows only sequential order which is a disadvantage.

Zip disks: It is similar to floppy disks. They have a less magnetic coating as compared to which allows more tracks per inch on the track surface.

Optical Storage Device

In the case of Optical storage devices, the signals are stored in the form of light. So 0’s and 1’s are converted into light information. Let’s learn about some of the optical storage devices.

CD-ROM: It stands for compact disk read-only memory. When you add or write any data in the CD it is known as burning the CD. It is basically ROM where data can be read but once written cannot be rewritten or erased.

DVD-ROM: Used for high-quality video and has better storage such as 4GB to 18GB.


In this tutorial, you learned everything about hardware and how computers work? So with this knowledge, you are a computer hardware pro and you can easily diagnose your systems!