Because dances are often relatively short in length, composers before the 1700s used to group dance pieces together in sets. Composers like Bach composed sets of dances in a much more formal way and called these sets of dances dance suites.
Dance suites were very popular in 1700s and were written for orchestras or solo instruments. The following clips are from Bach's French suite No. 5, for solo harpsichord, although they're played on a piano here.
For a dance suite to be called a suite, it had to contain the four most popular dances:
Those are the main four dance types. Other dances could often be sandwiched in between the sarabande and the gigue, such as:
Dance Suites were often preceded by a slow, stately piece of music called either a prelude, overture or sinfonia.