Trumpet is commonly used in classic and jazz ensemble, which is a brass wind instrument of the Aerophone family. It is made of brass tubing bent twice into a rounded oblong shape. Sound is produced by blowing air through closed lips into the mouthpiece. This produces a vibration of air column inside the instrument.
The mouthpiece has a circular rim, providing a comfortable environment for lips vibration. The cup directly behind the rim channels the air into a smaller opening. Trumpets have three or four piston valves. These valves increases the length of the tubing when engaged. This in turn lowers the pitch. The pitch of the trumpet can be raised or lowered by using a tuning slide, pulling which lowers the pitch.
Read more about Trumpet here
Here are small videos explaining the basics.