PSU,Because I don't know the difference between these two names I've heard,that is Modular and Non-Modular PSUs.Which one is good in terms of performance.Or just they're both same?
non Modular - all the cables are permanently attached. So you might end up with some cables still in your case that aren't attached to anything. Resulting in slioghtly more messy wiring than otherwise needs to be.
Modular, Semi-Modular or not Modular does not affect performance in anyway. Being modular allows you as a builder to use less cables and thereby have better cable management inside your case.
non Modular - all the cables are permanently attached. So you might end up with some cables still in your case that aren't attached to anything. Resulting in slioghtly more messy wiring than otherwise needs to be.