Hydrogels are one of the most fascinating classes of biomaterials. Highly versatile, they can be used in applications ranging from drug delivery to tissue engineering. In this nanomodule, you will explore the different types of hydrogels based on their origin, as well as the key bonding mechanisms that create their three-dimensional networks and define their unique properties. Since the bonding type ultimately dictates function, understanding these interactions is essential to unlocking the full potential of hydrogels in biomedical innovation.