Proxy Glossary - Every Term Explained in Plain English

The proxy industry is full of jargon that gets thrown around without explanation. Here is every term you actually need to know, in plain English.

Proxy types

Residential proxy - an IP address assigned by an internet service provider to a real home device (a phone, router or computer). Residential IPs look like genuine consumer traffic to websites, which makes them harder to block than datacenter IPs.

Datacenter proxy - an IP address hosted in a commercial data center rather than assigned to a home. Fast and cheap, but the IP ranges are well known to anti-bot systems and get blocked more easily on protected sites.

ISP proxy (static residential) - a residential-registered IP hosted on datacenter-grade infrastructure. Combines the trust of a residential IP with the speed and stability of a datacenter connection, and stays assigned to you rather than rotating.

Mobile proxy - an IP address assigned by a mobile carrier to a phone on a 4G or 5G network. Because carrier-grade NAT shares each IP across thousands of real devices, mobile IPs are the hardest for anti-bot systems to block.

Session behavior

Rotating session - a proxy connection where the IP address changes on every request, or on a set time interval. Useful for high-volume scraping where you want to distribute requests across many IPs.

Sticky session - a proxy connection that keeps the same IP address for an extended period (minutes to hours), then rotates. Necessary for tasks like logging into an account, where the site expects the same IP throughout a session.

Network and identity terms

ASN (Autonomous System Number) - a unique identifier assigned to a network operator, like an ISP or hosting company. Anti-bot systems use ASN data to distinguish real consumer ISPs from datacenter and hosting providers.

CGNAT (Carrier-Grade NAT) - a technique mobile carriers use to share one public IP address across many customers at once. This is why mobile proxies are so hard to block - blocking a CGNAT IP would block thousands of real, unrelated mobile users too.

Browser fingerprinting - the practice of identifying a device by combining dozens of signals (canvas rendering, WebGL output, installed fonts, screen resolution, timezone) into a unique profile, independent of IP address. A clean proxy alone does not defeat fingerprinting.

Success rate - the percentage of requests through a proxy that return the real, intended content rather than a block page, CAPTCHA or empty response. The single most important metric when evaluating a proxy provider for a specific target.