Wow. This thread gave me a headache. RAM is a generic term for memory (Random Access Memory) and people getting confused because something says DDR2 and then something else says RAM... so whats better? hahaha I love non-techies. DDR2 is the 'type' of RAM.
For future reference, if something says it has "2gb of RAM", the only thing you can count on is the fact that there is a quantity of 2gb. This is not enough of a description to tell you what TYPE of ram. SDRAM < DDR < DDR2 < DDR3
Not to mention you can get into the normal Single Channel DDR(1,2,3) memory or Dual Channel, etc... there are plenty of variables to consider and not just the quantity.