MEMS gyroscopes are used to measure the angular velocity of objects. According to the number of axes, MEMS gyroscopes can be divided into single axis, two axis and three axis. The different number of axes means that MEMS gyroscopes can measure objects in different axes, such as x,y, and z axes. The biggest difference between these three MEMS gyroscopes with different coaxial numbers is the number of axes, and their accuracy level has always been at 400 deg/s.
These three MEMS gyroscopes not only change in the number of axes, but also further enhance the function of MEMS gyroscopes with the increase of the number of axes. When it changes from single axis to two axis, MEMS gyro increases the function of attitude control, and three-axis MEMS gyro because it can measure the angular velocity of x,y,z three axes, it is equivalent to a three-axis measurement unit in a sense, and the inertial system/north finder can be developed on this basis, adding different algorithms to change it into different systems.

For more information: https://www.ericcointernational.com/gyroscope/mems-gyroscope