Definition of poker pair
A "poker pair" or "pair in pocket", one might say, is a pair in the hole. A "poker pair" is when we receive a pre-flop pair in our hidden hand. The poker pair should not be confused with the pair we can make with the flop. If we have AK in hand on a flop K-2-3, we have a pair. If we have KK preflop, we have a poker pair. If we receive 2 random cards in Texas Hold'em, we have a 1-in-16 chance of receiving a poker pair.
Don't overestimate your poker paires
Many poker players are in love with the poker paires. Of course, if you have a pair of aces, kings or queens, there's something to celebrate. But when you have poker pairess like 22, 33, 44, 55 in the UTG position, it's probably a good idea not to overestimate them. These types of hands on an aggressive table will be losers in the long run. Most players will open them, but if you analyze your database on a good sample hand sample, you'll find that you don't make money with these hands in early positions, especially if you're playing on full ring (FR) tables.