What is Cross-linking and what is the function of Crosslinking?

Hi Friends,
What is Cross-linking and what is the function of Crosslinking?

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.

Cross linking is used to refer the process of linking one site to another site and provide a way to allow the accessing to it. - It doesn't need to be owned by the same person as it provides the methods that have been be built on the Internet.

Cross linking is used to refer the process of linking one site to another site and provide a way to allow the accessing to it.

It doesn’t need to be owned by the same person as it provides the methods that have been be built on the Internet.
It provides the users with reference sites that consist of the contents similar to the viewing of the site of the document with certain defaults.
It serves the purpose to display the page on the search engines using search engine optimization techniques and methods.