The document discusses several key components of a computer system: The power supply unit (PSU) provides alternating or direct current to components. The motherboard holds the central processing unit (CPU), RAM, graphics card and other parts. The CPU processes instructions to run the computer, with single core CPUs handling one instruction at a time and dual core CPUs handling two simultaneously. Other components include read-only memory (ROM), random access memory (RAM) in forms like DRAM and SDRAM, and basic input/output system (BIOS) firmware that controls booting and basic functions.