What does max mean on 24x max CD-ROM drive?

CD-ROM (Compact Disc Read-Only Memory) drives that are over 16x have max written next to it. When max is written next to the speed or on the drive, it indicates that the CD-ROM uses constant angular velocity, to access its data. Originally, CD-ROM drives utilized CLV (Constant Linear Velocity), which accessed data slower or faster by changing the speed of the motor to transfer the data at a steady flow.

With CAV (Constant Angular Velocity), the CD (Compact Disc) rotates at a constant speed, which means a 32x speed CD-ROM, for example, can access the data 32x on the outside layer. However, when approaching the middle of the CD-ROM drive, the access speed can decrease close to 20x.