Newbie question - what is difference between a "template" and a "skin"?

[filburt1]

Simplifed: templates are just text defining the page's layout. Style sets include templates, and replacements; replacements define color attributes and such. Style sets sometimes contain graphics, too, but they're not included in normal .style files that vBulletin uses.

Don't worry, I was confused to the difference about vB's templating system when I first bought vB