Each boat has a TCF (time correction factor) based on the size of boat, type of sail etc. It allows a fair race to take place between different kinds of boats. Much like a golfing handicap allows players of different skill levels (size of boat) to play against each other, without the most highly skilled player (biggest boat) winning all the time.
The Estimated Finish Time is the time when we think boat will actually reach the finish - the time the boat will physically arrive there. The Corrected Finish Time takes the finish time, and applies (multiplies by) the TCF (handicap).
The leaderboard is then sorted in that order, so you can see who will "win" out of the group of boats. This is an imaginary time, but allows comparison of a fleet of disparate boats.