A quick overview on how computers work

This is just a rough description of a modern computer:

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The most important components are:

  • CPU: Central Processing Unit, executes all the software.

  • RAM: Random Access Memory, the main memory. Holds all the data that running programs are using and the programs themselves. Does not persist data, everything is lost when power down.

  • HDD / SSD: Hard Disk Drive / Solid State Disk, persisten data storage bigger and slower than main memory.

  • GPU: Graphical Processing Unit, draws stuff on screen and sends it to the monitor. Can also do some computations (GPGPU).

  • USB: Universal Serial Bus, connection for all external devices: mouse, keyboard, printer, scanner, camera, …

  • System Bus: Connects all the internal and external components together. This is the main bottleneck of the system.

  • LAN / WLAN: Local Area Network / Wireless Local Area Network, connection to other systems.

  • BIOS / UEFI: Basic Input Output System / Unified Extended Firmware Interface, when the system is turned on this is the first program that runs loads the operating system from disk.