Complex sentence: PokerTracker imports and parses the hand histories that poker sites write to a computer during online play in order to store the resulting statistics/information about historical play into a local database library for self-analysis as well as strategic analysis.
Split into simpler sentences: PokerTracker imports and parses the hand histories that poker sites write to a computer during online play. It then stores the resulting statistics/information about historical play into a local database library for self-analysis as well as strategic analysis.