wunder beta

🔎 How Search Engines Work

Follow a search engine from crawling and indexing through query interpretation, ranking, and the limits of an evolving web index.

3
lessons
~20 min
to learn
🤖 Technology
subject
Adults
level
Start the course →

What you’ll learn

  1. CrawlExplain how search engines discover and fetch web pages.Crawlers follow links, consult discovery sources, and schedule fetches under access and resource constraints.
  2. IndexDescribe how fetched pages become searchable records and candidate matches.Processing extracts content and signals, while inverted indexes make term-to-document retrieval fast.
  3. RankExplain how query interpretation and multiple signals shape eligible results and their presentation.Ranking combines relevance, quality, context, and graph evidence; presentation and index limits shape what you finally see.

Questions this course answers

What is the main job of a crawler?

Crawlers discover URLs and fetch representations; indexing and ranking happen in later stages.

What does an inverted index make efficient?

It maps terms to postings lists of documents, producing candidates without scanning every document.

Why is PageRank not a complete ranking formula?

PageRank is a graph-based signal; useful ranking systems combine many signals for a query and context.

Grounded in trusted sources

  • https://developers.google.com/search/docs/crawling-indexing/overview
  • https://developers.google.com/search/docs/crawling-indexing/overview-of-google-crawling
  • https://developers.google.com/search/docs/crawling-indexing/overview-of-google-indexing
  • https://developers.google.com/search/docs/appearance/ranking-systems-guide
  • https://developers.google.com/search/docs/crawling-indexing/robots/intro
  • https://support.microsoft.com/en-us/bing/how-bing-delivers-search-results

Every Wunder lesson is built from real, reputable sources — never invented.

Related Technology courses

📱How Recommendation Algorithms Work🔗How Blockchain Consensus Works🏧How ATMs Work💳How Credit Card Payments WorkWHHow Warehouses Work🩻How CT Scans Work🛗How Elevator Safeties Work🔧How Tunnel Boring Machines Work

Wunder is a personalized learn-anything platform — tell it any topic and it builds a beautiful, fact-checked course in minutes, with narration, a knowledge check, and a college-style University track.

Browse more Technology courses · All topics · Home

© 2026 Wunder Learning LLC · Terms & Privacy