DDR 2 / 3 / 4 / 5 what does it mean?

Ok so i'm new to pc gaming but planning to build my own pc at the start of next year and i keep hearing and seeing this DDR stuff. So what exactly does it mean ? I'm guessing the higher the number the faster it is as i've seen it on gpu's and ram i think so if anyone could explain this to me it would be much appreciated.


it's hard to explain



so readup and enjoy!

also, the CPU standard is ddr3 and the GPU standard is gddr5 (g for graphic I believe)

intel is pushing ddr4 for cpus around 2014.

as for gddr4, they just kinda skipped it like the Nvidia 3xx series

ok, thanks for the links. 

I think i understand all this better now and it's starting to make some sense