Catenation is the self-linking of atoms of an element to create chains and rings.
The capacity to create double bonds, the ability to form different types of double bonds, and the configuration of the element's molecular orbitals surrounding the atom are all electronic and steric factors that affect catenation.
Examples of catenation
Catenation happens most easily in carbon, establishing covalent bonds to build larger chains and structures with other carbon atoms.
Carbon is not the only element capable of generating such catenae; silicon, sulfur, and boron are just a few examples.