In the first chapter of Gyroscopes: Types, Functions and Applications, the operating principle, types and applications of fiber-optic gyroscopes are summarized, and a novel slow light gyroscope based on coupled resonators is introduced. Following this, two signal processing techniques are discussed, each for a different type of gyroscope noise. These two techniques are then combined to produce a general technique for improving the accuracy of a gyroscope. The main methods of creating compact passive optical gyroscopes and their development trends are examined in the closing chapter.