Tor: What can Tor protect me from, and what can’t it?

Short answer

Tor helps separate your network address from the sites you visit and limits some forms of tracking and censorship. It cannot protect a compromised device, make an unsafe download harmless, or prevent a site from recognizing an account you log into. Threats differ, so identify what you are trying to hide and from whom before relying on Tor as your only protection.

Sources

Tor Project: About Tor Browser, Tor Project: Tor Browser best practices.