Repairing operations improve the shapes, processing them with complex algorithms:

Shape processing - processes one or more shapes using various operators.
Suppress faces - removes chosen faces of a shape.
Close contour - closes an open contour asnd miodifies the underlying face.
Suppress internal wires - removes internal wires from shapes.
Suppress holes - removes holes with free boundaries on a selected face.
Sewing - sews faces or shells.
Glue faces - unites faces coincident within the given tolerance.
Glue edges - unites edges coincident within the given tolerance.
Limit Tolerance - tries to set new tolerance value for the given shape.
Add point on edge - splits an edge in two.
Change orientation - reverses the normals of the selected faces.
Remove internal faces - rebuilds the topology of solids by removing the faces are shared by several solids.
Remove extra edges - removes seam and degenerated edges from the given shape.
Fuse Collinear Edges within a Wire - removes selected vertices from a given wire in case if adjacent edges are C1 continuous.
Union faces - unites on a given shape all faces sharing the same surface.