What's an EV trained pokemon and how do you trainded them?

Question

l've always wondered whats an EV trained pokemon and how do you train them

Answer 1

EV is effort value. In other words every pokemon you fight gives a certain value. Gyrados would give out two attack stats because he has high attack. Magikarp would give two speed.

This is a hidden value. You cant really see it but everytime you fight a pokemon you get an ev. Each ev helps boost a certain stat such as attack. If you wanted a rally strong attack stat gyrados then you would fight pokemon with high attack to get better attack than special attack.