Many road bikes and other bicycles that require very high air pressure use Presta valves because they are slender and enable a cyclist to inflate tires with a simple pump with attached chuck (pump head) and no hose. Presta valves can be easier to pump than Schrader, because they have no valve spring to overcome. The small diameter of the Presta valve requires a smaller hole in the rim (important for narrow rims!).
Schrader valves, the wider ones like you see on a car tire, are also universally used. A spring closure makes them simple to use because you can press the inflation chuck onto them at an automobile service station. For hand pumps, a screwed or lever chuck provides the valve depressor. The depressor not only makes inflation easy, but is also necessary to check pressure in the tire.
There are many bike pumps available that are integrated and can be used for both Presta and Schrader valves. If you have a Schrader valve pump, there are adapters available to make it work on Presta valves.