• Northbridge Connects to the CPU, memory, PCI-e and Southbridge
  • Southbridge Connects to the I/O peripherals, Northbridge and BIOS

The components in a computer can be grouped into 2 categories according to their function:

  • Category 1: The Computer System (the core system)
    1. The Central Processing Unit (CPU) — also known as a processor.
      1. CPU will fetch the next instructions in a program from the memory and execute the (fetched) instruction
      2. The CPU can retrieve (= read) instructions from the computer memory and execute them
      3. The CPU can also retrieve (= read) and store (= write) data from/to the computer memory
    2. Memory (a.k.a. Random Access Memory (RAM)     
      1. memory is a huge storage component that stores:
        1. Instructions of computer programs
        2. Variables (= data) used in the computer programs
    3. CPU and memory inter-connected by the system bus made up of 3 buses (address bus, data bus and control bus)
      1. Bus inside a computer = a group of electrical wires that are used to transmit similar information
        1. transmit the ID information of a device (= address/identifier)
        2. transmit information between devices (= data/information)
        3. transmit commands to devices (= control/command)
  • Category 2: Peripheral devices (a.k.a.: Input/output devices)   
    1. Input devices (e.g., mouse, key board, scanner, disks…)
      1. Enables human users to enter data into the computer (= machine)
      2. The data will be stored inside the computer in such a way that the computer can use it effectively
    2. Output devices (e.g., terminal, printer, disks, …)
      1. Enables the computer to show data stored inside the computer to a human user in a “humanly” way
    3. Peripheral devices are auxiliary devices that allow users to:
      1. Enter inputs into the computer
      2. Obtain outputs from the computer


  1. ASUS P5AD2-E Motherboard. (n.d.). Retrieved July 20, 2021, from
  2. Northbridge (computing). (2021, June 08). Retrieved July 22, 2021, from typical north/southbridge layout
  3. Structure of the computer memory (RAM). (n.d.). Retrieved July 22, 2021, from