What bike is better?

A Moped/Scooter (if they even the same thing), or a motorbike. I need something to get from one end of campus to the other. Nothing expensive but durable. I would like it to last for the next few years with as few problems as possilbe. Gas friendly would be great too.

Get an old Honda Elite SA50. They are great on gas(90mpg).
Very reliable, and really easy to work on for maintenance. Best of all in most states you license them as mopeds.

Honda sold somewhere around a trillion of them in the states and can be found in some odd places rather cheap.
Ride Safe

Scooter would be best, they have automatic trannys.
Usually, you have to shift a motorbike.

if you really want to go gas friendly and even envirinment friendly buy a bicycle

No Dear, mopeds and scooters are not the same thing.
Mopeds generally look like a bicycle with a small engine. A scooter generally has fairly small wheels and a U shaped appearance.
I would say that a scooter would be the way to go. They are usually easy to maintain, get great gas mileage and have a top speed around 45mph.

If you're just getting from one end of campus to another, walk or use a bicycle. If you're going off campus, motorcycle.

Honda's CRF 230
OR
Yamaha's TTR 230

Get a Vespa. Best motorscooters around.

http://www.vespausa.com/index.cfm?spl=1

go for one of them electric bangers cheap and reliable

Go to your local Yamaha dealer and look and test drive the Morphous scooter.

Vespa. After 60 years, they are still around.

i would go with a scooter then you can cary all your books ect easily, and they have some nice ones out now.