Meditation is a form of brain training, requiring a lot of discipline and practice. You are essentially teaching yourself how to alter your brain's function.
The difference is like watching TV versus playing a video game. It may look similar at first, but they are two entirely different things.
This is an interesting read if you're into meditation as it relates to science:
http://psyphz.psych.wisc.edu/web/News/Meditation_Alters_Brai...
A good place to start.
You can find it here: http://zencast.wordpress.com/category/kusala-bhikshu/
His talk at Google:
In the same vein meditation is not the same thing either. From my point of view it's about being mindful about one's surrounding without analyzing it, just observing. It's a state that I find actually quite difficult to really achive.
Actually, any type of meditation is difficult. (The other general type of meditation I know of is where you focus on a specific sound (or mantra) and repeat it over and over, either out loud or in your mind.)