In Computer-Aided Design (CAD), a revolve is a modeling operation that creates a 3D shape by rotating a 2D profile around an axis. Revolve features are commonly used to create cylindrical or axisymmetric shapes, such as shafts, bottles, bowls, or other objects with circular cross-sections.

To create a revolve feature, designers first create a 2D profile or cross-section, typically using sketch tools such as lines, arcs, and splines. The profile defines the shape of the object when viewed from the side, and should be created on a plane that is perpendicular to the desired axis of revolution.

Once the profile is created, designers specify the revolve parameters, such as the axis of revolution, the start and end angles, and any draft or offset distances. The software then generates the 3D solid by rotating the profile around the axis, creating a solid volume.

Revolves can be used to create a wide variety of shapes and features, such as:

1. Cylindrical shapes: Shafts, pipes, and other objects with constant circular cross-sections can be easily created using revolves.

2. Tapered shapes: By specifying different start and end angles, designers can create tapered or conical shapes, such as funnels or nozzles.

3. Partial revolves: By specifying start and end angles that are less than 360 degrees, designers can create partial or sectioned revolves, such as a quarter-circle or a half-pipe.

4. Hollow shapes: By revolving a profile with a hollow center, designers can create hollow or shell-like shapes, such as bottles or containers.

Revolves are a powerful tool in parametric modeling, where the geometry of a model is defined by parameters and relationships. By creating a revolve feature from a parametric sketch, designers can easily modify and update the model by changing the dimensions and constraints of the sketch, without having to recreate the entire feature.

Most CAD software packages provide a range of tools and options for creating and editing revolve features, including different axis options (such as edge, line, or point), direction options (such as one-direction or symmetric), and merge options (such as join, intersect, or cut).

By mastering the use of revolve features, designers can quickly and easily create complex axisymmetric shapes from simple sketches, and can explore different design variations and iterations with ease.