Before you start assembling a computer on your own, you need to understand some basic theoretical foundations, so that when you choose computer accessories, you know their functions and roles, as well as the corresponding accessories at different levels of configuration of the computer can play out the overall performance of the function and use of scenarios that can be met.

As an example to make it easier to understand, there is no way a 1.0L engine installed in a 4.5L pickup truck will allow the pickup truck to fulfill its cargo carrying function. Similarly, a pickup truck with tires that are mounted on a Beetle will not be able to run properly.