In recent years, high-stiffness, high-strength, and lightweight composite materials have gained recognition as a significant cutting edge technology with a potential to generate efficient power, reinvent the high-efficiency transportation sector, offer new carriages for storage and transportation of reduced carbon fuels, and enhance renewable energy production. Presently, the structural components manufactured from polymeric materials in conjunction with various fibrous materials provide a cost-efficient solution for almost every industrial sector. A polymeric composite material is a multi-phase structure in which reinforcing fibers are integrated with a polymeric matrix material, resulting in a synergy of mechanical characteristics that cannot be realized from either of the components alone. This book familiarizes the readers with fibers and polymeric matrix materials, which are the constituents of a typical polymer composite. It is believed that this book can serve as a greatly valuable reference for a varied range of readers, including scientists, engineers, policymakers, and professors. This book is also useful for teachers and students from different backgrounds including textile engineering, materials science, fiber science and technology, mechanical engineering, nanotechnology, chemical engineering, medical sciences, and environmental science.