All fountains eject sparks from the ground up into the air. Heights vary depending on the size and quality of the fountain, from a few feet up to 20ft+ for the biggest ones.
Conical fountains tend to be the same effects all the way through, which are typically either gold, silver or crackling. Some also contain flecks of colour. This type of fountain usually starts very low and gradually works its way up to full height by the end.
Cylindrical fountains tend to actually be batteries of several different fountains all fused to fire one after the other. Here, the usual display is one of changing effects as each tube progresses. Many finish with a plume of intense crackles. Some multi-effect fountains like this can last for a very long time; over 2 minutes is possible.
An example of a conical fountain in action is shown below.