Beginner glossary Q&A: complication, caliber, jewel count, power reserve · RWI-02414

Caliber is the movement's model designation, like a part number. Two watches from different brands can share the same caliber family with different finishing or regulation. On a spec sheet it tells you what's inside and roughly what service parts are available. It doesn't tell you how well that particular example was adjusted.

A complication is any function beyond hours, minutes and seconds. A date window counts, technically, and so do a chronograph, GMT hand or moon phase. More complications usually mean more parts, more thickness and more service cost. For a first everyday watch, decide which functions you'd really use before treating them as value.

Jewel count describes bearings used in a movement design; it is not a quality ranking. Compare the documented movement architecture and service support rather than assuming a higher count makes one watch better.