What are the different types of rockets?

Answer 1

Micro Rocket:

Micro rockets are meant as an introduction for youngsters in the world of amateur rocketry. These small rockets are build out of light materials as cardboard and balsa-wood; but they do allow to explain the principles of rocket propulsion and the behavior of rockets in flight (stability).
They use commercial motors and don't use a electronic ejection system for the parachute.
Micro rockets typically attain an altitude of 25 to 200 meters and can thus be launched from relatively small areas.

Model Rocket:

These are mostly commercial scale model kits or custom build rockets with commercial available elements. Materials used are cardboard, balsa-wood and plastic; metals are forbidden. Commercial motors up to type "G" (=160Ns thrust) are the only allowed motors in this category and use a parachute or streamer on board to slow down the rocket during descent which is ejected by a small explosive charge on top of the motor.
Some rockets have also a payload section (egg, camera, small electronic experiment, ...). This category also knows several official competitions.
You can achieve heights up to 1000m and even more. It quite easy and fun to build and launch model rockets.
The 'Vlaamse Raket Organisatie' doesn't focus on model rockets, but you are welcome if you need some practical assistance. If you would like to launch this types of rockets, the Euro Space Center Rocketry Club is the place to be for you.
The NAR and Tripoli are the most well-known international organization. They have local clubs and organizations in almost every country (were rocketry is allowed).

High Power Rocket:

High Power Rocketry is a step further in model rocketry. These rockets are much bigger and more more materials are allowed to use. They can have flight electronics on board for measurements, flight control and tracking, in flight video capturing, ... They always use commercial motors.
Because bigger and stronger motors are involved, you need a certification to buy these motors. This certification can be achieved if you succeed in the appropriate certification flight recognized by the NAR and Tripoli.
These rockets can achieve heights of several kilometers.
You will not see this type of rockets in Belgium because of the limited launch possibilities.

Mini Rocket:

These rockets are a first introduction to experimental rockets. The main objective is to get the rocket safe back to the ground with a parachute released by an electronic system. Because of their size they have to be launched from a launch tower and on military ranges.
They may contain some metallic parts, weigh about 1 to 2 kg and reach altitudes below 100 meters.

Amateur (Experimental) rocket:

These rockets have diameters from 4 to ... cm, contain metal parts and electronics and can reach altitudes of a many kilometers. Every flight incorporates measurements of the flight path and these values are stored in onboard memory or transmitted real time to the ground.
The chemical and thermodynamic properties of the rocket-fuels is determined with static testing .
It is clear that these types of rockets can only be launched from suitable launching sites (typically military sites) and that all the required safety measures have to be taken into account when dealing with the fuels.

Answer 2

The main types of rockets are solid rockets, liquid rockets, and hybrid rockets. Solid rockets use a fuel that is already mixed and solidified, while liquid rockets use separate liquid fuel and oxidizer that are mixed and burned. Hybrid rockets combine elements of both solid and liquid rockets, using a solid fuel with a liquid or gaseous oxidizer.