Composite materials have emerged as important materials in various industries due to their unique combination of properties, blending high-strength reinforcement with the matrix of the same or different materials. This chapter provides an overview of the fundamental aspects involved in understanding composite materials. The content explores the definition of composites, their classification based on matrix and reinforcement materials, and the inherent advantages that arise from their collaborative combination of both matrix and reinforcement. Additionally, discussions on different types of reinforcements, mainly metallic and nonmetallic fibers, and their limitations are presented, providing insight into how they influence the final properties of the composite. The mechanical behavior of composites, including factors like stiffness, strength, durability, fatigue, and fracture, is essential to recognize, as understanding these aspects is vital for optimizing material selection in diverse applications. The role of interfaces between the matrix and reinforcement is examined, highlighting their impact on overall performance, especially when dealing with the crack arrest phenomenon. Furthermore, the chapter explores challenges associated with composite materials, such as delamination, matrix fatigue and fracture, the nature of applied load, including accidental loads during the assembly of structural components, environmental degradation, and finally, the anisotropic nature of composites, which requires addressing. The application of composites in aerospace, automotive, construction, and other industries is investigated, revealing their potential use in each sector. The importance of computational modeling and simulation techniques in predicting the behavior of composite structures is also briefly addressed, emphasizing their role in the design and optimization processes. Finally, a comprehensive understanding of composite materials is crucial for unlocking their full potential in various applications. Limitations in using composites are related to high cost and time to manufacture parts. These are two main critical issues for industries when numerous parts are required to fabricate in a short time. Lastly, the content of this chapter aims to provide a foundation for engineers to further explore and contribute to the evolving field of composite materials.
