Formatting an external hard drive for Mac and Windows

Hello,

I just bought a brand new Seagate Expansion Desktop Drive (2TB) and am trying to work out how to format it. I want to move all my photos and movies to it from my laptop so i have more space. I have a Mac OS X 10.5.8 laptop but i also wanted to make sure it was compatible with other Windows computers in case i need to use it on someone else's PC.

I've read through a few posts over the net and i am getting confused as i'm not IT-intelligent at all. I've seen there are possibly 4 different format types.

Any help would be much appreciated.

Thank you!