The Violin, Viola, Cello and Double Bass are known as the “violin family” since they all look alike and are orchestra instruments. All these instruments have strings made of a material that will produce a sound. The strings are activated by fingers, a pick or a bow. A hollow box is put under the strings to make the sound louder. The length and tension of the string affects how high or low the notes are, tension is how tight or slack they are.
The Violin is the most commonly used member of the modern string family and is the highest sounding instrument of that group. Overall length of the violin is 32.5 inches.
The Viola is the middle voice of the violin family, between the Violin and the Cello. The Viola is bigger than a Violin and the exact size has never been agreed on, so each Viola varies a tiny bit.
The Cello is bigger than the Viola and is placed between the knees of a cellist and the cellist sits on a high stool, behind the instrument.
The Bass or Double Bass is taller than a person and wider than a wheelbarrow.