There are two main types of bike tube valves - Presta and Schrader. Here is what they look like.
As you can see, the Presta valve is more slender than the Schrader valve. Pretty much all bikes sold in the U.S. before the 1980's came with Schrader valves. But with the advent of the 10-speed bike - the very popular Schwinn Varsity comes to mind - road bikes rims were outfitted with Presta valves. So one way to remember the difference between the two valve types is:
In oher words, the Presta valve is the more "modern" of the two valves. Note that the Presta valve has a removable inner core and that the rider has to open and close the valve by twisting the tiny little lock top. The Schrader valve has less mechanics involved, and usually bikers will seal a Schrader valve with a plastic top cap. Schrader valves are the type used for cars, and if you ever need air at a gasoline station, the air compressor will have a Schrader end fitting.
For more information on these two bike valve types, see: