Meaning – The Central Processing Unit is the brain and heart of the computer, and consists of all the components required by the device to function properly. The main part of the CPU is the motherboard, which features the processor, graphic processor, and other conduits for interfaces such as displays, mouse, printer, keyboard and other peripherals.
When you buy a computer (desktop), the majority of the price is made up by the CPU, while the external devices are exponentially cheaper.
If you are an enthusiast, then the first thing you want to do while assembling a custom build PC, is to construct the CPU.
Example of usage – “The gamer decided to build the ultimate gaming rig, and invested heavily into the best spec CPU money can buy.”