It can be hard figuring out what the heck all those numbers and acronyms mean, so here are all the acronyms in Pokemon and what they mean and do.
Stat Acronyms:
BST: Base Stat Total, or the sum of a Pokemon's 6 base stats. This ranges from 180 (Sunkern) to 780 (M-Rayquaza and M-Mewtwo). It means nothing in battle :P
IVs: IV is short for Individual Value. Like Nature, IVs are chosen at semi-random when the pokemon begins to exist. Each Pokemon has 6, one for each stat. They are a hidden value from 1-31 inclusive. these greatly impact stats, as well as the move Hidden Power. For competitive play, you will generally want Pokemon with 31 IV in all stats, unless they use the move Hidden Power.
EVs: Effort Values. A value from 1-252 inclusive in each stat. At Lv100, 4 EVs in a stat increases said stat by 1. A total of 510 EVs are allowed on each pokemon across all stats.
HP: Health Points
Atk: Attack
Def: Defense
SpA, SpAtk: Special Attack
SpD, SpDef: Special Defense
Spd: Speed (not to be confused with SpD)
Type Effectiveness Acronyms:
STAB: Same Type Attack Bonus. tl;dr if the type of the move matches the type of the pokemon using it, it's power is increased by 1.5x
SE: Super Effective
NVE: Not Very Effective
Move Acronyms (there are a lot more, these are the common ones):
HP [Type], HP (if type already stated): Hidden Power (not to be confused with Health Points)
HP (with no type specified and it's obviously not a stat): Hydro Pump
EQ: Earthquake
BP: Bullet Punch (not to be confused with Battle Points from the ingame Battle Tower/Frontier/Subway/Maison)
SE: Stone Edge (not to be confused with Super Effective)
SD, DD, QD, NP, CM: Swords Dance, Dragon Dance, Quiver Dance, Nasty Plot, Calm Mind, respectively. Stat boosting moves
I might add more here later
Format Acronyms:
OU: Overused. The default format.
BL: Between Level. Honestly you will never see this.
UU: Underused
LU, RU: Little Used or Rarely Used, them mean the same thing.
NU: Never used
NEU, PU: I have no idea what Smogon's means, but POs means Never Ever Used and it's below NU.
LC: Little Cup. Only unevolved pokemon that can evolve
CC: Challenge Cup. RANDOM TEAMS!
BF, BF6v6: Battle Factory. See Platinum.
That should be good enough for now. Here is a nice competitive start guide to help you with the rest.
http://www.smogon.com/dp/articles/intro_comp_pokemon