How many rotating axes are in cylindrical coordinates?

In cylindrical coordinates, there are indeed one primary axis that is typically considered a rotation axis. This is the axis around which the cylindrical coordinates are defined, specifically the z-axis. In this system, points are represented using three coordinates: the radial distance from the z-axis (r), the angular position (θ) around the z-axis, and the height along the z-axis (z).

The z-axis serves as the vertical axis, while the radial distance and angular coordinate allow for movement in a circular path, but only one of those axes truly describes a rotational motion around a central point, which is the z-axis. Thus, specifying the number of rotating axes correctly identifies the z-axis as the singular rotational axis in the context of cylindrical coordinates.