Road pedals have a quill on the outer aspect of the pedal to prevent your shoe from sliding sideways:



Track pedals are built on the same base as the road pedal, but lack the quill to gain additional cornering clearance (track bikes can't coast through corners and are thus more susceptible to pedal strike). Road riders with wide feet often prefer these to quill pedals:



Touring pedals also lack the quill and may be wider than track or road pedals to accommodate regular shoes. These also have a serrated cage to help hold a non-cleated shoe: