The trumpet is a timeless instrument and has the highest voice in the brass family. There are many different varieties including the cornet, flugelhorn and specialty options such as the piccolo trumpet (mainly used in symphony orchestras and chamber ensembles). Students and those just starting out often choose a Bb (B-flat) trumpet. These are regularly seen in for jazz, concert and marching bands.
Some of the questions answered below
Student trumpets are machine made and intended to be highly economical and long-lasting. In most cases, a student horn is a perfect choice for the initial 2 or 3 years. They perform very well but lack some of the higher-end features and construction seen in intermediate and professional models. As well they normally are crafted with a two-piece bell instead of a one-piece.
Intermediate trumpets come in two basic types and are an ideal choice for those looking for an upgrade after the first couple of years. The first type is a student horn with additional features to improve sturdiness and tuning like 1st valve slide/thumb hook, deluxe cases, silver plating and adjustable 3rd valve slide stops. A second choice is intermediate horns which are comparable to professional ones but manufactured in a less expensive manner that could impact resonance, aesthetics and intonation.
The main moving parts of the trumpet are the valves or "valve piston" as the player pushes down on them to make different notes. The quality of the horn is largely dependent on the ease of use and accuracy of the valves. Student horns typically have nickel-plated valves which are hard, sturdy and work well even with less frequent cleaning. They tend to be a bit looser in order to move freely as long as they are well oiled. A large number of intermediate horns are made with Monel® alloy which is softer than nickel. Sturdily designed, it's quite resistant to corrosion and is comfortable on the fingers. Lastly professional horns are normally made of either Monel or stainless steel.
Valves should play quickly and smoothly and need to be well lapped (polished and honed for a smooth, close fit) to reach this goal. Higher grade trumpets frequently have hand-lapped valves, performed by an expert in the field to ensure flawless performance.
All trumpets are constructed of durable brass; however there are a number of different finishes to choose from. Lacquer is sprayed on then baked in an oven to ‘cure' it; this finish is available in all levels. This process makes for a slightly darker sound. Silver-plating is applied by electroplating. This is more resilient than lacquer and slightly brightens the sound. Gold-plating is only available on professional horns and slightly darkens the tone.