A search engine is a service that helps you find information on the internet by searching through billions of web pages to match your query. Think of it as a librarian for the entire internet - you describe what you are looking for, and the search engine finds the most relevant pages in seconds.
Search engines operate through three main steps. The first step is crawling. Automated programs called crawlers (or spiders) follow links from page to page across the web, discovering and downloading content. The second step is indexing. The search engine analyzes the content of each crawled page and organizes it in a massive database, categorized by keywords and topics. The third step is ranking. When you enter a search query, the engine retrieves matching pages from its index and ranks them by relevance. Google uses over 200 factors to determine rankings, including content quality, backlinks from other sites, page loading speed, and mobile-friendliness.
Google dominates the search market with approximately 90% global share according to StatCounter's 2024 data. In Japan, Yahoo! JAPAN is also popular, but it actually uses Google's search technology under the hood. Microsoft's Bing holds a smaller share but has gained attention by integrating AI chat capabilities into its search experience.
The relationship between short URLs and search engines matters for SEO (Search Engine Optimization). When a search engine crawler encounters a short URL, it follows the redirect to discover the destination page. The type of redirect affects how search engines treat the link. A 301 redirect (permanent) passes most of the link's SEO value to the destination, while a 302 redirect (temporary) may not transfer the same authority. For websites that rely on search traffic, choosing the right redirect type in a URL shortening service can influence search rankings.
Search engines cannot index everything on the web. Pages behind login walls, content blocked by robots.txt files, and pages with noindex tags remain invisible to search results. The portion of the web that search engines can access is sometimes called the 'surface web,' while the rest is known as the 'deep web.' You can find related books on Amazon.