This site may be a little confusing for you if you are not familiar with swimming terms. This is where you can come if you want to find out what I mean by 10 50′s fly back on the :50.
One lap: one length of the pool.
25: one lap (25 meters)
50: two laps (50 meters)
IM: stands for individual medley. A set that goes butterfly, backstroke, breaststroke, freestyle
Freestyle: a stroke, often called the crawl
Butterfly: a stroke, using dolphin kicks and arms moving at the same time. Considered by many to be the hardest stroke.
Backstroke: a stroke, swum like upside down freestyle
Breaststroke: a stroke, using frog kicks and horizontal pulls. (my worst stroke)
Flipturn: the turn at the wall that you do at the end of every backstroke and freestyle lap that you do. You do a frontflip right in front of the wall and push off. It is a lot faster than just turning around normally.