Plastics are polymers, typically versatile, cost-effective, and require less energy to produce than alternative materials such as ceramics, glasses, and metals. Polymers can be manufactured to have many different properties, and the use of these polymers in various fields has surpassed other materials. Petroleum resources are being extensively used to produce polymers; however, the excessive usage of these petro-based polymers raises ecological and environmental issues. Over the last few decades, green and natural renewable materials have increasingly become a research focus due to environmental issues and nonrenewable petroleum resources. Biobased and biodegradable nature of biopolymers makes them one of the favorite choices to be utilized for the preparation of environment-friendly materials. This chapter discusses and highlights biobased and biodegradable polymers and common factors affecting polymers as well as nanocomposites preparation and their utilization in a diverse range of products.