Mountain bike front suspension. This will usually be controlled by a single valve. Bicycle suspension can be implemented in a variety of ways and any combination thereof. The best suspension springs for mountain bikes will feature a positive and negative air chamber in one leg. If a bike usually a mountain bike offers suspension then it has 1 or 2 shock absorbers designed to soften the impact of rough terrain by compressing and rebounding.
A mountain bike with large knobby tires and straight handlebars but with neither front nor rear suspension. A mountain bike equipped with a suspension fork for the front wheel but otherwise a rigid frame. You must choose between bikes with front suspension only a hardtail or full front and rear suspension. A well designed bike will have geometry and sizing built around the suspension travel and will be all the better for it were at a point with mountain bikes where not only has technology improved but so has the design teams experience in.
Some points of comparison. Bicycle suspension is the system or systems used to suspend the rider and bicycle in order to insulate them from the roughness of the terrain. Bicycle suspension is used primarily on mountain bikes but is also common on hybrid bicycles. Mountain bikes can usually be divided into four broad categories based on suspension configuration.