A caseback is the rear cover of a watch case, serving both functional and aesthetic purposes. It protects the internal components of the watch, such as the movement, from dust, moisture, and damage. There are three main types of casebacks: exhibition, closed, and solid.

An exhibition caseback features a transparent window, often made of sapphire crystal or mineral glass, allowing the wearer to view the intricate workings of the watch movement. This type is popular among enthusiasts who appreciate the craftsmanship and mechanical beauty of the watch's inner workings.

A closed caseback is typically opaque and does not allow visibility of the movement. It is often made of metal and may feature engravings or brand logos. Closed casebacks provide a more traditional appearance and can offer better protection against water and dust.

A solid caseback is similar to a closed caseback but is usually more robust and thicker, providing enhanced durability and resistance to external elements. Solid casebacks are often found in dive watches or those designed for rugged use, where additional protection is necessary.

Each type of caseback serves a specific purpose, catering to different preferences and functional requirements in watchmaking.