In this chapter, we have discussed the basics of composite materials, types, properties, and applications. Students will learn the fundamentals of composite materials and their importance in many engineering fields. Composite materials can be defined as “the combination of a hard and a soft material” or “these are the materials composed of different parts with specific ratios”. This chapter comprises of the advantages and disadvantages of composites and also focuses on different fabrication methods of preparing composites. Fundamentals of nanocomposites and their recent improvements are also added in this chapter.