I have started out reading books on vb,and i have got a good basic idea how vb works....but! in all my books..it doesnt explain this simple question i have..

When you create a function,can you "name" it whatever you want? So if i wanted to create a function named
Formatharddrive() all i would have to do is input the code and will it work?Or is there a predetermined set of functions that we all have to live by.(for vb)
Thank you in advance for any help.