Not necessarily. A string quartet can and will play many types of classical literature - not all pieces have four movements.
nuno flores string quartet or corvonuno string quartet
Goldner String Quartet was created in 1995.
Alba String Quartet was created in 2003.
FourPlay String Quartet was created in 1995.
Vertavo String Quartet was created in 1984.
Quartet = Four (4).
nuno flores string quartet or corvonuno string quartet
Concord String Quartet was created in 1971.
Emerson String Quartet was created in 1976.
Australian String Quartet was created in 1985.
Oberlin String Quartet ended in 1959.
Oberlin String Quartet was created in 1955.
Hollywood String Quartet was created in 1939.
Orion String Quartet was created in 1987.
Atrium String Quartet was created in 2000.
Cypress String Quartet was created in 1996.
Tokyo String Quartet was created in 1969.