From my understanding int and Int32 are the same thing in C#, but I’ve read a number of times that int is preferred over Int32. So, what is the reason? Should I care?
The two are indeed synonymous; int will be a little more familiar looking, Int32 makes the 32-bitness more explicit to those reading your code. I would be inclined to use int where I just need ‘an integer’, Int32 where the size is important (cryptographic code, structures) so future maintainers will know it’s safe to enlarge an int if appropriate, but should take care changing Int32s in the same way. The resulting code will be identical: the difference is purely one of readability or code appearance.