What is a web crawler? Fetching a page does not mean indexing it
Explain crawler discovery and fetching and distinguish indexing and training, checking logs, identity and access rules.
Understand the concept
A crawler automatically fetches pages, often for discovery and updates. Fetching does not establish indexing, serving or model training. Crawlers have different purposes and claimed user agents are not proof. Verify identity and distinguish access, content and later processing.
Fetching pages differs from creating search results
Google lists different automated clients and RFC 9309 defines crawl rules. Discovered URLs still need processing after fetches. One request interval does not establish long-term policy. Search and training crawlers are not interchangeable under an AI-bot label. Identify the target client and applicable controls rather than assuming universal effects.
Inspect responses and verified request logs
Inspect live status and text and verified crawler records, distinguishing rejection, server errors and success. Requests do not prove indexing and user-agent strings should not grant privileges. No logs or requests were inspected here. For script-heavy content, verify actual readable information rather than screenshots alone.
Keep server behavior and crawl controls consistent
Recheck robots, caches and paths after deployment. Use current identity mechanisms rather than old IP lists. Include logs and recovery, not hit counts. Report observed fetches separately from unknown index outcomes. Crawling only obtains content; visits do not prove usefulness.
Checked sources
These sources support the concepts and methods described here. Examples and test scope are labeled separately; check the version of the tools you use.