The word bot covers several generations of automation.
Crawlers were the easy case
Early crawlers mostly declared themselves and followed predictable retrieval patterns. The defensive problem was policy and load, not deception.
Automation became operational
Fraud, scraping, and abuse workflows changed the incentives. Operators began tuning infrastructure, identity, and timing to survive production controls.
Agents change the surface
AI agents make intent harder to classify because useful automation and abusive automation can share the same browser and API paths.