Search Engine Submission, as the name says, is the process of submitting a specific URL to search engines like google, yahoo, and bing. Search Engine Submission is important because it tells the search engine to crawl your site more often at regular periods of time.
Though Search Engine Submission is not a very effective way of search engine optimization, it is still a golden rule to submit your URL to search engines for faster indexing of new pages.
Search Engine Submission is done in google by the webmaster "add url" page, where you can submit a url and add comments on the address that you specified