Overview of a Desktop Computer

A typical desktop computer consists of:

Computer System Unit (CSU)

Also known as:
- Computer case
- Computer chassis
- Computer tower
Material:
- Usually steel or aluminum
- Can also be made of plastic
Function:
- Encloses and protects all main components
- Allows for upgrades (e.g., second hard drive, better video card)
- Easier to open and upgrade compared to laptops

Front Side Features:
- Power button
- Optical disc drive
- Audio outlet for headphones
- Multiple USB connections
Back Side Features:
- Connections for:
  - Power
  - Monitor
  - Keyboard
  - Mouse
  - Internet
  - Other peripherals
- Typically more connections than the minimum required for expansion

Motherboard:
- Placed vertically (common layout)
- Accessible inputs/outputs and expansion slots located on the back
- Houses the Central Processing Unit (CPU)
  - Often has a large fan for cooling
- Contains main memory
Storage Components:
- Hard Disk Drive (HDD): for mass storage; connected via wires to the motherboard
- Optical Drive: accessed from the front of the case
Power Supply:
- Located at the back
- Typically has its own fan for cooling

Different shapes and sizes of computer system units:
- Full tower
- Mini tower
- Slim case
- Small form factor
Orientation:
- Tower models usually stand upright
- Smaller models can lie flat to save space

The computer system unit is essential for housing and protecting the computer's main components while allowing for future upgrades.