IPv4
The fourth and most widely used version of the Internet Protocol, giving every connected device a numeric address like 192.168.1.1, with about 4.3 billion unique addresses.
Full Definition
IPv4 (Internet Protocol version 4) is the foundational addressing scheme of the internet, using 32-bit addresses written as four dot-separated octets (e.g. 203.0.113.42). It supports approximately 4.3 billion unique addresses — a number that was exhausted years ago, driving adoption of NAT and IPv6. In the proxy industry, IPv4 addresses are the currency: residential, datacenter, and mobile proxies are all primarily IPv4. Because the IPv4 space is finite and well-documented, every address's ownership can be looked up in WHOIS and ASN databases, which anti-bot systems use to classify traffic.
