equity is how often you win the pot with a specific hand (i.e. the percentage of the pot that is "yours"). Pokerstove is a free program you can use.

two examples:
Board: 6c 7c A

equity win tie pots won pots tied
Hand 0: 43.737% 43.74% 00.00% 433 0.00 { AhKs }
Hand 1: 56.263% 56.26% 00.00% 557 0.00 { 9c8c }

you flop OESFD vs TPTK, you are actually a favorite to win, you can safely call any bet (or ideally raise)

Board: 6c 7c Ad

equity win tie pots won pots tied
Hand 0: 66.640% 66.52% 00.12% 48074 86.50 { 66+, ATs+, KQs, AQo+ }
Hand 1: 33.360% 33.24% 00.12% 24023 86.50 { 9c8d }

OESD vs a range, you could call most bets if you think you have implied odds if you hit.

I feel this is a shitty post, cuz i've been drinking...

moral of the story: download pokerstove