Kinematics is the study of motion apart from the cause of that motion. In this chapter, we extend those basic ideas of the previous chapter to motion and deformation in three-dimensional solid bodies. The aim is to characterize multiaxial deformation in a way that can eventually be used in a model of material behavior. As it was for the axial bar, the concept of strain, a relative measure of deformation, is ideal for that purpose. Hence, this chapter is all about extending the concept of strain to the multidimensional setting. The concepts are first formed in the simple context of homogeneous deformation, mostly in two dimensions. Once the basic framework is in place, we extend the ideas to nonhomogeneous deformations.