44=VP$IP - voluntarily put $ in pot (preflop) - a measure of loose/tightness, expressed as a percentage. 44 means this player is voluntarily entering the pot with 44% of all hands. the reliability of this stat depends on how many hands it is based on.

2=PFR - Pre Flop Raise - what percentage of the time does this player raise or reraise preflop, expressed as a percentage. a measure of passive/aggressiveness. again, the reliability of this stat depends on how many hands it is based on.

a 44/2 is entering many pots (loose) and raising few hands (passive).