Integers

I had researched and dived to so many resources for the fundamentals of Pyhton, this is the first amazing one that I come across. Till now I didnt know we could get the Bin, Oct and Hex in python numbers… wow

May sound stupid, but why does bin(), oct(), hex() return a string? Does it have to deal with underlying programming of python seeing alphanumerics as a string? I apologize I like knowing how things work.