There are four types of fronts normally recognised in weather forecasting. They are the warm, cold, stationary and occluded fronts, each of which has a different influence on the local weather. The descriptions given below are not scientifically absolutely accurate but are helpful in understanding how they influence our weather. If you wish to see a more accurate description of frontal systems take a look at the Wikipedia entry and you can find out all about frontogenesis which includes horizontal deformation, horizontal shearing, vertical deformation, differential vertical motion, latent heat release, surface friction, turbulence and mixing, and radiation. I'd stick to the simple version for now!
The four fronts are illustrated on synoptic charts (forecast charts) in the following way. The semi circles and triangles show the direction of travel of the front.
A warm front is best described as a moving mass of warm moist air which moves forward which then rises over a colder air mass (note:colder but not necessarily cold). It is a very simple description but illustrates ncely how it functions.