The significant difference between a band and an orchestra is that orchestras usually play classical music, while bands have more options as to what type of music they play. An orchestra is said to be a group of musicians playing classical music together. An orchestra can even have over a hundred musicians.
A large orchestra is a symphony, or a philharmonic orchestra, while a small orchestra can have over thirty musicians. The smaller orchestra is called a chamber orchestra. Bands, on the other hand, can include concert bands, brass bands, or marching bands.
The concert band has musicians playing woodwind, brass, percussion instruments, and brass band play such as the trombone, tuba, trumpet, and drums. Marching bands typically perform outdoors, much of the time at sporting events, and they usually march all together in place. Bands can generally play any music they want to.