Like its name, the Hybrid is a combination of features from both mountain and road bikes. The wheels are not as sturdy on trails as those of a mountain bike, nor are they as thin and fast as those of a road bike on paved surfaces. But hybrid wheels are versatile enough that you could ride comfortably on either surface. Hybrids tend to have a relatively high number of gears and upright handlebars.
Pro: Good for riding on multiple surfaces. A little less expensive than a road bike.
Con: Mountain bikes are a better choice for trails and road bikes for road riding.