Ted,
If you are an IBM-PC user currently you will have to buy a whole new suite of software, Few PC-compatible applications have been ported to the Apple OS and vice-versa.
It is the computer equivalent of leaving the known universe and entering a parallel one in which everything you were familiar with is different, and yet it all seems to work well enough. It is also the end of all your old computer problems - and the start of all your new ones.
"Anyone can make a mistake but it takes a computer to have a catastrophe."