The action of making search engines aware of your new web page by manually submitting a URL in order to have it indexed faster.
It is a common belief that this is not necessary, as the crawlers are pretty good at discovering new content and will eventually index your website or web page if they have links pointing to it. However, sometimes it takes a while before your brand-new website/web page pops up in the SERPs. A few days is normal, but if it takes a few weeks you might want to consider submitting it manually to the search engine.
You can manually submit your website to Google by adding your XML sitemap in the Google’s Search console.