Mini-USB is a small trapezoidal connector that predates micro-USB. It appeared in the early 2000s on digital cameras, MP3 players, external hard drives and early smartphones, at a time when devices were shrinking but USB-A was too large to fit.
Compared with the later micro-USB, mini-USB is noticeably thicker and its connection is generally considered less durable over repeated use, since the mating mechanism relies on friction against the sides of the plug rather than a spring clip. Mini-USB never reached the same near universal status that micro-USB later achieved on phones.
Mini-USB largely disappeared from new consumer electronics once micro-USB became common, and it is now mostly found on older cameras and some musical and technical equipment that has not been redesigned. If you still own a device with this port, a mini-USB cable is the only reliable way to connect it, since adapters for this older connector are less common than for micro-USB. See the connector overview for the full picture.
