What is the meaning of Revolving?

moving around a central point.

Relating to an account or line of credit where balances and credit roll over from one billing cycle to the next, such as a credit card.

present participle and gerund of revolve

The act of something that revolves or turns.

The process where you either take an non-closing linear shape or a 2D shape, take a 3D axis as the pivot, and basically revolve the linear shape around the axis to get a 3D object. (e.g. taking a 2D triangle and turning it into a cone, taking a circle and turning it into a sphere, taking a long U-shape and turning it into a test tube object)

Source: wiktionary.org