A PC case holds all your expensive hardware and also offers aesthetics to your build. They also offer add-ons like extra trays for your hard drive, DVD Rom, and more USB ports.
PC cases come in different sizes and types. The sizes are mini ITX, MicroATX, ATX, and EATX.
While each case has its own benefit, the size of a case doesn’t matter if it offers good airflow and fits all your components.
Airflow is the most important thing to check when purchasing a case, so even if a case is small and still able to cool your component temperature, then it’s a good case.
A PC case can be large but doesn’t provide good airflow and if there is not enough airflow, your component might overheat and maybe, even get damaged. So always check the airflow of a case before even thinking about the size.
NB: Most large cases provide better airflow than small ones.
If you are building a high-end gaming pc, I would recommend you build in a large case with good airflow, because large pc cases are mostly going to accommodate large radiators for better cooling.
Large cases are likely going to have more hard drive trays, so if you plan of using more hard drives, then a large case will suit your needs.
However, if you are building a low to mid-range PC, a small case will be perfect.
Also, know that most compact cases are very expensive.
A small or large case doesn’t matter if it has good airflow and also fit all your component without modding them. However, larger cases always have better airflow compared to small cases.