airline lingo explained please
 

STOPOVERS- how do you get them? ---CIRCLE TRIP-what are they? OPEN SEGMENTS- what is this? Guess I'm just not understanding !

Stopover--when you stay more than four hours at a connecting point (24 on international flights--US to Canada or reverse is not international) even though there was a legal connection during that time.

Legal connection--there's a certain minimum time to catch the connecting flight. This varies by airline and airport. For instance, the minimum from United to Air Canada at O'Hare is 26 minutes. AC is well placed there, so that's not too bad, unless you're going to Winnipeg. Airlines generally will not sell tickets with connecting times below minimum; if you put one together yourself, it's at your own risk.

Circle trip--one that includes more than just two cities.

Open segment--a round trip in which you don't fly one segment. For instance, I might go CHA-ATL-LAX-ATL but leave off the final ATL-CHA.

What you describe is an OPEN JAW. Starting at one point - ending at another point. (starting CHA - ending ATL)

OPEN SEGMENT will be one segment within your itinerary you are allowed not to book flight time / date.

Open jaw also includes the turnaround point--e.g YYZ - LHR, CDG - YYZ.

One caveat on circle trip. A fare that allows stopovers can create a multi-city itinerary that is, in fact, a point-to-point.

For example, the J fare from YYZ to HKG allows unlimited stopovers. So you go YYZ-ORD-LAX-HKG-YVR-YYZ.

This looks like a circle fare. But in fact, the fare calculation will show YYZHKG and HKGYYZ.

You can find some of the more common terms explained at:
http://www.trip.com/help/glossary/