What is Submission?
Submission is the act of sending a URL to be indexed by a search engine manually or with the help of automated tools. While paid inclusions do ensure crawling, Google Search Console’s free submissions only request indexing. In this case, lower submission practices are better than mass spam-automation tactics. In general, consistently submitting new or edited URLs enables faster server-side content discovery.
Some examples of submission are perusing the Google Search Console Inspection tool, queueing XML sitemaps on Bing Webmaster Tools, or automating pinging sitemaps.
Related terms: sitemap, paid inclusion, indexing, crawl request