Always a favourite with everyone, the rocket has a part in almost every amateur display.

Most rockets comprise of three main sections. The head, normally made of card or plastic, contains the effect itself. This is mounted on top of a cylindrical "motor", which the fuse ignites. The motor contains solid fuel propellant and can accelerate the rocket to several hundred miles an hour in some cases. When the motor has burned through, a reverse charge explodes into the head, igniting the payload.

These components are mounted on a long stick, normally made of wood or dowel. The stick is inserted into a launch tube which is normally a piece of plastic piping or conduit.

Rockets vary considerably in size and shape as manufacturers fight for supremacy of the sky. In recent years, packaging has changed to include metallic reflective casings, and double, triple and even quadruple effects are available.

All rockets have one thing in common: A very short effect. Unlike cakes or candles, the rocket's effect normally explodes in one go and is therefore over in a few seconds. A small number of rockets manage to achieve a longer "hang time" with persistent effects such as gold glitter or fish, but durations of more than a few seconds are rare.

The majority of rockets contain a "display" effect. This means something pretty or colourful, sometimes accompanied by other sounds such as crackles. Some rockets have a pretty tail when they take off and nearly all rockets bang loudly as a side effect of the payload detonating (even if the effect itself is quiet).

At the more expensive end of the market, particularly from brands such as Kimbolton or Weco, you can expect some very imaginative combinations of colour and sound effects.

As you would expect, large display rated rockets pack a bigger punch than smaller, garden rockets. The relationship is not necessarily directly related to price however, we have found that you have to pay a lot more to achieve a slightly bigger effect. This is why many smaller rockets actually offer better value for the majority of displays.

Rockets are sometimes described by a weight in ounces. This is the equivalent weight of lead shot that would fit into the motor and therefore has little or no bearing on the quality of the effect. A 4oz rocket may have a more powerful motor than a 2oz rocket, but this does not guarantee it has more effects in the head.

Some manufacturers do quote the actual payload content in grams, and this can be used to make very general comparisons between various sizes.

Descriptions sometimes refer to a rocket as having an "aluminium" motor. In this case the motor is housed in a metal tube rather than a card one. This is generally regarded as an improvement in build quality of the rocket as a whole, but does not improve the actual effect. This seems less of a selling point recently as the quality of fireworks continues to improve each year and such features become the standard.

Some rockets concentrate solely on making a loud bang and these are known as signal or maroon rockets (and sometimes "flash" or "report" rockets). These are just plastic or card tubes filled with powder and the bigger ones can be very loud.

Like airbombs, very loud "bang rockets" have become the bad boys of fireworks and have been casualties of new limits on powder content and noise.

Surprisingly, professional displayers rarely use rockets. Instead, the majority of aerial effects at a professional display are created by aerial shells, which are banned from sale to the general public. This is why many rockets are compared to aerial shells. A rocket that can imitate an aerial shell in action is considered a good one.

Manufacturers have realised this and have taken the concept a step further by producing rockets that specifically look like they are a shell on a stick. In general these produce very good performances with the better ones doing a good job of imitating their professional cousins.

These rockets are often called "ball" rockets (such as Lunig's Ball rockets), shell rockets, ballhead rockets and so on.

A new arrival in the last few years, rocket "pods" are a tube or box containing a number of smaller rockets (typically 6-8) which are fused together. You light one fuse, and all the rockets launch together. This is intended to make multiple launching of rockets safer, at a premium of paying more per rocket than buying singles. These pods look set to evolve further with volleys of 25 rockets now on the market.