Definition of FR
FR stands for "Full Ring". A full ring table is a poker table with 9 or 10 players. There are head-to-head tables with 2 players, shorthanded (SH) tables with 4-5 or 6 players and there are full ring (FR) tables which are usually 9 player tables (between 8 and 10 depending on the cardroom). Shorthanded tables are generally contrasted with full ring tables. Each table will have its own style of play. In general, tournaments are more popular in full ring and cash games are more popular in shorthanded.
Are you more SH or FR style?
Each table has its own particularity. At the SH tables, there is more action, players are more aggressive, blinds come back more often, there is more variance. At the RF tables, the blinds come back less often, the players are more conservative and the hand that wins the pot is always a little stronger than at the SH tables. There is also probably less bluffing in RF than in SH. The variance is also a little lower in RF. On the other hand, the profit per hour is greater at a SH table since you will be playing more hands per hour.