A circular cylinder is a cylinder generated by parallel lines through the points of a circle, with the generating direction not parallel to the plane of the circle. The term also denotes the solid bounded by a portion of this surface and two parallel circular bases (Kern and Bland 1948).
A right circular cylinder has its generating lines perpendicular to
the base plane. Otherwise, the circular cylinder is oblique.
Thus "circular" specifies the shape of a base, whereas "right"
specifies the direction of the generating lines. For a right circular cylinder of radius 
, the lateral surface has
equation 
when its axis is the 
-axis. Without end caps and extended infinitely
in both directions, this is the circular cylinder used as an example of a constant
mean curvature surface and a limiting Delaunay
surface.
