Photoshop CS

Hi everyone
I've been looking extensively trough the FAQ since I got photoshop last month and I'm really a mess at it to say the least,also the 'beginners'tutorials are too advanced for me LOL
But what I wanted to ask is : I got Adobe Photoshop Cs v.8.0 ...and what IS that exactly? Is there any difference,say, between photoshop Cs and photoshop 8 or whatever? Because everytime I look through the tutorials I can't decide If I have to follow the ones for CS or the ones for PS 8,please help and forgive my being so utterly dumb
Silvia