What is a solid figure with one circular base and one curved surface?

A solid figure with one circular base and one curved surface is called a cylinder. In a cylinder, the circular base is parallel to the other circular base (if there is one), and the curved surface connects the edges of the base, forming a three-dimensional shape. If it has only one base, it can be considered a cone, which has a circular base and a single curved surface that narrows to a point.