IV are short for individual values, and no pokemon has perfect values.
They pretty much determine how strong or weak the pokemon is
At least thats what i hear
EV are short for Effort Values
Effort Values are gained each time you beat a pokemon to a certain stat, like Attack for example
For every 4 points, the stat gains 1 point, and when the pokemon lvls up, that point is given to the stat.
Thats why people talk about EV training, to gain a lot of EVs into a certain stat to make it really high