Cross Linking is the art of creating links within a website. In a very traditional layout you might have a home page and then to other pages (page A and page B). The home page would contain links to both.

A cross-link is a bond that links one polymer chain to another. They can be covalent bonds or ionic bonds. "Polymer chains" can refer to synthetic polymers or natural polymers.

Cross linking refers to the process of linking between two sites. Whether or not they are owned by the same person, cross linking is the process on which the internet is built. It allows users to reference sites with content similar to that which they are already viewing, and may be of further interest to them.