Hi,
No, what matters is the size of the chassis and the size of the motherboard that could fit into it.
It helps if you can tell us what manufacturer an model it it is on your current computer.
There are lots of different chassis, but if You are looking for a ATX mobo here is the specifications:
https://sv.wikipedia.org/wiki/Advanced_Technology_Extended
[Edit] My answer was based on the original question, I didn't see the rest of them...hehe
Please remember that if You whish to extend your computers power in regards of processor and graphics and memory - be advised to make sure that not only the chassis is the limit but also the power supply and of course the chassis again.
Best regards from Sweden