Some airlines call them roundtrips, other's call them turns, but no matter what you call them they are the most desirable trips if they are worth good time.
Yesterday I had a rather easy trip where I just flew from STL-ATL-STL. I was only gone about 4.5 hours and didn't work that hard. Granted this shorter turn wasn't worth much in pay, its still nice to be able to go to work and come home in the same day. For those Flight Attendants working for the majors, a turn can consist of STL-LAX-STL. Worth about 8 hours of pay and still the same result.
These trips usually go senior and are for the flight attendants who don't really need the perdium as much but still fly for the benefits. At TWA we used to call them "Big Girl Turns", because the senior FA's held them and they only had to do them 8 days a month or so.
The difference between a turn as apposed to a 2-4 day trip is that the perdium on the turn is taxable where as on a 2-4 day trip it is non-taxable. All I know is that I like flying them and hopefully will be able to hold them in the future.
Until next time, enjoy your flying, fly safe and as always I support our troops.