It refers to the act of submitting a URL to search engines in order to make it aware of its existence.

In addition to submitting a URL to a search engine for their due consideration, addition information like email address, contact information will have to be furnished. There are different policies which are to be followed while adding URLs to search engines. These policies vary a great deal from one search engine to another. While for few search engines, mere submission of URLs is fine. For others, individual pages need to be submitted.Generally, two types of submissions are followed- manual and automated. In the case of former, individual form fields needs to be filled for adding every page. In the case of latter, all information required can be filled in one go.