What component does the system unit of a computer house?

The system unit of a computer primarily houses the motherboard. The motherboard is a critical component because it serves as the main circuit board that connects all other components of the computer, including the processor, memory, and various input/output devices. It allows these components to communicate with each other and is instrumental in the overall functionality of the computer system.

While the other components such as the power supply unit, hard drive, and cooling fan may reside within the system unit, they do not define the unit itself. The power supply unit distributes electrical power, the hard drive stores data, and the cooling fan helps regulate temperature. However, it is the motherboard that acts as the backbone of the computer system, making it the primary component housed within the system unit. Understanding the role of the motherboard can help students grasp how computers process information and communicate internally.