This is stuff you really don't have to worry about on any modern system, unless you're saving binary files/packets to be portable between different architectures -- that's when you definitely should prefer the <cstdint> types.
Go ahead and learn memorize all the other intricate types if you wish, but only ancient consumer computers are ints 16-bit (Win16 API). If you run any modern OS (Windows or MacOSX/Linux/Unix, BSD, etc.) you will have 4-byte (32-bit) ints. [Embedded world will be different, check your manual]
Wow didn't know there was soo much to just datatypes.. thanks guys! It's a bit confusing but I guess I will just use the standard int and use modifiers only if I need them. hehe.