Indexing is the process by which search engines crawl and store web pages in their database. After a search engine's crawler (bot) visits a page, it analyzes the content and adds it to the search engine’s index. This indexed data is then used to retrieve relevant pages when a user submits a search query.
Indexing helps search engines understand what a webpage is about, allowing them to rank it appropriately based on relevance and authority. If a page isn’t indexed, it won’t appear in search engine results, meaning it can’t be discovered by users. Proper indexing involves ensuring that a website’s content is crawlable, relevant, and follows best practices for SEO.