What is the difference between a rigid body and a deformable body in the context of static mechanics?

A rigid body is an idealized solid object that does not deform under applied forces, meaning the distances between points within the body remain constant regardless of external forces. In contrast, a deformable body can change shape or size when subjected to forces, leading to internal stress and strain. In static mechanics, rigid body analysis simplifies calculations by assuming that bodies remain unchanged, while deformable body analysis requires consideration of material properties and deformation.