Full definition
An antidetect browser is what you use when you need multiple "different" users running on the same machine without any of them detecting that they're actually the same physical computer. Each profile has its own canvas fingerprint, WebGL fingerprint, font list, audio context, screen resolution, timezone, language, fonts, and proxy.
Used for: managing multiple social media accounts (each account gets its own profile), affiliate marketing across multiple ad platforms, e-commerce account farming (within ToS), QA testing across many user contexts, and scraping where each session needs to look like a fresh independent user.
Top picks: Multilogin (most polished, $99–$199/mo), GoLogin (cheaper, $24+, has free tier), AdsPower (popular in Asia), Dolphin Anty (lightweight). All work with any major proxy provider.