Where can I find out what the "deadlifts, planks" etc mean?

I'm so useless with what these exercises are and wondered if there's a website I could go on to find out.

i.e. I've been doing bodypump for 3x months now and only realised the other day I do dead rows (or a barbell row as I've seen others call it) instead of a dead lift :-( I thought I was doing a dead lift!

When I see on these forums people are doing planks, bicep curls, chest flys etc it would be good to know what they actually are :-)

Thanks, Kel