Ram Usage

If I do not open parallels, am I still only using half of my RAM on my Mac?
How do I see how much Ram I am using?

If you download a widget called iStatpro for dashboard, that will tell you how much memory you're taking up, and if you pay around with the preferences, it will also tell you what each program you are running takes up. Here's the link: http://www.apple.com/downloads/dashboard/status/istatpro.html. And about parallels, if you don't have it running, it won't take any RAM up, unless you don't fully quit out of it.

how do you fully quit out of it? just pressing the red x in the top right corner right?