There are many different types of trumpets. However, the most common one is the so-called Bb trumpet. There are smaller sizes of trumpets, for example, the piccolo and the pocket trumpet. A fun fact is that a pocket trumpet actually has the same tube length. However, it is bent more than the normal one, and that's why it looks smaller. On the other hand, the piccolo trumpet has a shorter tube, and that's why it can play an octave higher.