Abstract This chapter provides an introduction to plasticity models in the one-dimensional setting. The phenomenology of plasticity is discussed together with concepts of isotropic and kinematic hardening. The additive decomposition of the strain is introduced along with the concepts of plastic strain and equivalent plastic strain. Plastic flow is discussed and defined, and complete models of plasticity are formulated with loading/unloading conditions. Both rate independent and rate dependent (viscoplastic) models are discussed. In addition, basic numerical methods for evaluating plasticity models are presented.