A solid rocket motor consists of the fuel and the oxidiser mixed together in a solid propellant grain. Solid rocket motors are storable, easy to load into a rocket and can be relatively high thrust.

A solid rocket motor cannot be turned off after it has been ignited. It burns until all of the propellant is exhausted.

A hybrid rocket motor consists of two components which are separated from each other, namely the fuel and the oxidiser. Normally, the oxidiser is either in the liquid or gaseous phase, and the fuel is solid, although it is possible, but less common, to have a liquid fuel and a solid oxidiser. Hybrid rocket motors are storable, although once the oxidiser is loaded into the oxidiser tank, the rocket needs to be launched, or the oxidiser just boils off. They are generally very safe, and are normally of a lower average thrust than similar solid rocket motors.

Some hybrid rocket motors can be turned off after ignition, although for simple operation, this is not the case with High Power Rocketry hybrids.