What is the meaning of '==' in C?

Question

What is the meaning of == and how does it differ from =?

How do I know which one to use?

Answer 1

I might add that in Finnish and Swedish keyboards. Pipe symbol; |; of OR is AltGr (the right alt) and < key. IF you are using Mac on the other hand it is Alt-7 key.

Gave me a lot of sweat when I first started typing on these keyboards.