Covalent bonds are a type of chemical bond where two atoms share electrons. This sharing allows each atom to achieve a more stable electron configuration, similar to that of the noble gases. For example, in a water molecule, each hydrogen atom shares an electron with the oxygen atom, creating a strong bond that holds the molecule together.
These bonds can form between nonmetals, such as carbon and oxygen, and can create various structures, from simple molecules like methane to complex ones like DNA. The strength and stability of covalent bonds are crucial for the formation of the diverse compounds that make up living organisms.