Collagen is the dominant component of the extracellular matrix of mammals. It occurs almost in all animal tissues. Collagen is a highly heterogeneous protein. The collagen protein family is characterized by great diversity in terms of structure, occurrence, and function. Up till now, 29 types of collagens proteins have been classified. The representation of individual types of collagen has certain common features. The most important property is the above-average mechanical strength that results directly from the spatial structure. Collagen is a building material for most tissues and organs. It also plays an important role in the process of cell growth and differentiation, which results from the specific structure of collagen fibers as well as their ability to adhere. The development of research techniques allowed to study in detail the molecular structure and properties of collagen. Therefore, collagen has become a subject of interest in many branches of science. Synthetic recombinant collagen fibers were developed as the basis of collagen biomaterials for medical applications, including implantology or gynecology. The specific structure of collagen also makes it applicable as a protein carrier in drug delivery systems (DDS), particularly in the treatment of cancer and genetic diseases. The use of tissue regenerative abilities and an interdisciplinary look at the properties of collagen and collagen-based biomaterials may constitute the future of medical development.