WEB INDEXING 

Web Indexing defines that the list of information in the web. It is basically a method of indexing the content of a website. Indexing means that the page is eligible to show up in Google's search results.

Search engine indexing collects, parses and stores data so that they can provide accurate information retrieval. Index design incorporates the concept from Mathematics, Informatics and computer science. An alternate name for the process in the context of search engines designed to find web pages on the Internet is web Indexing. 

WEB INDEXING IN SEO RANKING 

Search engines index websites in order to respond to search queries with a correct information as soon as possible. For this reason it stores information about Indexed web pages like keywords, title or descriptions in a database. This way search engine can quickly identify pages relevant to a search query. 

Google index your website for giving you ranking on your keywords. 

To check whether your site has been indexed or not go to google and then type -

                                                                        site:www.yourwebsite.com and then enter.

If you see your website pages are being listed in the search results then it means that your site has been indexed in Google otherwise not.