The subject of this paper are smart materials. The introduction provides an overview of smart materials and their historical development. The concept of smart materials and shape memory alloys is also explained. The following sections describe the thermomechanical behavior of shape memory alloys, including martensitic transformation, shape memory effect (one-way shape memory effect, two-way shape memory effect, multiple shape memory effect), as well as pseudoelasticity, superelasticity, and rubber-like behavior. The classification of shape memory alloys based on nickel, copper, and iron is also described. The paper further explores the applications of smart materials in major industries such as automotive, aerospace and medical. Additionally, an overview of ferromagnetic, piezoelectric and ferroelectric materials is provided, along with their shape memory properties and applications. The conclusion summarizes the key findings on smart materials, particularly shape memory alloys, and highlights their potential for broader applications in the near future.