What is an orchestra?
A modern orchestra is a large group of musicians who play (mainly) classical music. The musicians are organised in a semi-circle facing the conductor and the audience. They are grouped together according to the instrument they play.
An orchestra can be made up of more than 100 players divided into four sections or families: strings, brass, woodwind and percussion.
Who sits where?
The strings are left and right of the conductor at the front. The woodwind players come behind the strings. The brass are in the middle towards the back, and right at the back are the percussion instruments.
The conductor is in charge of controlling the sound the orchestra makes, whether it be all the instruments or just a few members of one section playing.