Hey there!
I hear you're having problems with the commonly used competitive battling terminology. Well, one of our distinguished members has posted a dictionary! The link Anti gave you does work very well and will give you an excellent place to start, but trust me, when you get deep into the competitive world... Things can get pretty complicated. Sooooo...
Here you go!
This dictionary will mostly help you with the common abbreviations, not really define what "walls" or "physical sweepers" are. But it will help you decipher stuff like, "NPLuke", "BoltBeam, and "Glis". Long story short, this dictionary is super user friendly, informative, easy to understand, and aesthetically pleasing. :D (it'll also help you if you need to brush up on Abilities or other standard things for competitive play)
Anyway, hope all this was helpful!
Oh.. and welcome to the CBC! :D It's nice to see some new faces around here. If you ever need help with anything about competitive battling or general forum etiquette, feel free to ask me or any of the other members here. We're all friendly, so don't hesitate to ask!
Have a nice day! :3