SEO Fundamentals – How Search Engines Work (Crawling, Indexing, and Ranking Algorithms)

What is SEO?

Search Engine Optimization (SEO) is the practice of improving a website so it ranks higher in organic (unpaid) search results.

Crawling

Search engine bots ('spiders') discover pages by following links across the web and reading sitemaps.

Indexing

Once crawled, pages are analyzed and stored in a massive database called the index, which search engines pull results from.

Ranking Algorithms

Search engines use hundreds of ranking signals to order results, including:

• Relevance of content to the search query
• Page authority and backlink quality
• Page speed and mobile-friendliness
• User experience signals (dwell time, bounce rate)