Full definition
A residential proxy routes your traffic through a real consumer's home internet connection. The IP address you appear to come from is one assigned by an ISP like Comcast or Vodafone to a real subscriber, not a datacenter. This is the highest-trust IP type because anti-bot systems can't flag the IP as a server.
The trade-off is cost (typically $4–$10 per GB) and pool refresh: residential IPs are constantly added and removed as real users go online and offline. Most providers source these IPs from SDK monetization programs where users opt-in to share their bandwidth in exchange for free apps or ad-blocking.
Best for: web scraping at scale, ad verification, social media management, sneaker bots, SEO tracking. Not ideal when speed matters more than stealth.