PCs are more customizable, making it more open to viruses, but you can do more stuff involving programming etc.
MACs are closed in so your less likely to have viruses, making it not as open as the PC.
So overall, if you're looking to be a programmer and tester, get a PC. If you want something just to look on the internet, do a few things, and have a nice looking and save computer, then a MAC is right for you. Then again, that's just an opinion.