How to use this glossary
Proxy marketing is full of jargon, and different providers use different words for the same thing. This glossary defines the terms you'll encounter when comparing and using proxies. Where we have a full guide on a topic, the term links to it.
A to D
Anonymous proxy. A proxy that hides your IP but reveals it's a proxy. See proxy anonymity levels.
Antidetect browser. A browser that manages separate fingerprints and profiles for multiple identities. See antidetect browser proxies.
API (proxy API). A programmatic interface to manage proxies, generate lists or check usage. Also used loosely for scraping APIs.
ASN (Autonomous System Number). The identifier of a network operator, such as an ISP or cloud provider. Websites use ASN to tell residential from datacenter traffic. Some providers offer ASN targeting.
Backconnect proxy. A gateway that routes your traffic through a pool of exit IPs, rotating them for you. See backconnect proxies.
Bandwidth. The amount of data transferred, usually billed per GB on residential plans.
Bot protection / anti-bot. Services like Cloudflare, Akamai, Datadome, HUMAN and Kasada that detect automated traffic.
CAPTCHA. A challenge to prove you're human. See CAPTCHAs and proxies.
CGNAT (Carrier-grade NAT). Sharing one public IP among many users, common on mobile networks, which is why mobile proxies are hard to block.
CONNECT method. The HTTP method used to tunnel HTTPS through a proxy. See how proxies work.
Concurrency / threads. The number of simultaneous connections you can run.
Datacenter proxy. A proxy with an IP from a hosting or cloud provider. See datacenter proxies.
Dedicated proxy. An IP used only by you. See dedicated proxies.
DNS leak. When DNS lookups bypass the proxy and reveal your location. See DNS leaks.
E to L
Elite proxy (high anonymity). A proxy that adds no identifying headers.
Exit node. The device or server whose IP the website sees.
Fingerprinting. Identifying a browser or device by its characteristics. See browser fingerprinting.
Forward proxy. A proxy acting on behalf of clients. See forward vs reverse proxy.
Gateway / entry node / super proxy. The address you connect to with a rotating proxy service.
Geo-targeting. Choosing proxy location by country, state, city or ZIP. See geo-targeted proxies.
Headless browser. A browser without a visible window, controlled by code. See headless browser proxies.
IP whitelisting (allowlisting). Authenticating by your source IP. See proxy authentication methods.
IPv4 / IPv6. The two versions of internet addresses. See IPv4 vs IPv6 proxies.
ISP proxy (static residential). An ISP-registered IP hosted in a datacenter. See ISP proxies.
KYC. Know-your-customer checks that providers run before granting access.
Latency. The delay before a response begins. See proxy speed test.
Proxy tip: A practical next step is to run a few requests through a commercial pool and watch what changes. Geonode supports HTTP, HTTPS and SOCKS5 and lets you switch between rotating and sticky sessions from the same endpoint. We walk through it in our Geonode proxies guide.
M to R
Mobile proxy. A proxy with an IP from a cellular network. See mobile proxies.
Pay-as-you-go. Buying traffic without a subscription. See pay-as-you-go proxies.
PAC file. A script that tells browsers which proxy to use for which URL. See proxy PAC files.
Peer. A residential device in a proxy network.
Pool. The set of IPs a provider can route you through. See proxy pool size.
Port. The network port a proxy listens on. See proxy ports explained.
Private proxy. A marketing term usually meaning dedicated. See private proxies.
Proxy chain. Routing traffic through several proxies in sequence. See proxy chains.
Rate limit. A cap on requests per IP or session. See rate limiting and proxies.
Residential proxy. A proxy with a home ISP IP. See residential proxies.
Reverse proxy. A proxy acting on behalf of servers.
Rotating proxy. A proxy whose IP changes automatically. See rotating proxies.
S to Z
Scraping API. A service that fetches pages for you, handling proxies and blocking. See scraping API vs proxies.
Semi-dedicated proxy. An IP shared by a small number of users.
Session ID. A parameter that keeps the same exit IP. See sticky vs rotating sessions.
Shared proxy. An IP shared by many users. See shared proxies.
SOCKS5. A protocol-agnostic proxy protocol. See SOCKS5 proxies.
Static proxy. A proxy whose IP doesn't change.
Sticky session. Keeping the same IP for a period.
Subnet. A block of IP addresses, such as a /24. Bans often apply to whole subnets.
Success rate. The share of requests that return the data you wanted.
TLS fingerprint (JA3/JA4). A signature of how a client negotiates TLS, used by bot protection.
Transparent proxy. A proxy that reveals your IP.
Unlimited bandwidth. Plans not billed per GB. See unlimited bandwidth proxies.
Web unblocker. A smart proxy that handles retries, fingerprints and CAPTCHAs. See web unblocker proxies.
WebRTC leak. A browser feature revealing your real IP. See WebRTC leaks.
Whitelisting. See IP whitelisting.
Ready to buy? Start with our guide to the best proxies.
Newer terms worth knowing
Proxy vocabulary keeps growing as browsers and protocols change. These terms turn up more and more in documentation and support threads:
ECH (Encrypted Client Hello). A TLS extension that hides the website's name in the handshake from networks along the path. It doesn't hide the destination from your proxy, which still receives the hostname. See HTTP vs HTTPS proxies.
MASQUE / CONNECT-UDP. IETF standards for carrying UDP, including HTTP/3, through an HTTP proxy. Used by some privacy relays; rarely offered by commercial proxy providers so far.
NO_PROXY. An environment variable listing hosts that should bypass the proxy. curl and Python read it, and so does Node.js when its built-in proxy support is switched on. See curl proxy.
QUIC / HTTP/3. The UDP-based transport behind HTTP/3. Ordinary HTTP proxies can't carry it, so browsers fall back to HTTP/2 through them.
Retry-After. A response header telling clients how long to wait after a 429 or 503 response. Honour it. See rate limiting and proxies.
robots.txt. The file where a site states which paths automated clients may crawl, standardised as RFC 9309. See ethical web scraping.
SNI (Server Name Indication). The hostname a client sends at the start of a TLS handshake, which lets one IP host many HTTPS sites. Visible to proxies and networks unless ECH is in use.
socks5h. The URL scheme curl, Python and other tools use for "SOCKS5 with DNS resolved by the proxy". See DNS leaks and proxies.
Sub-user. A separate set of credentials under one proxy account, usually with its own traffic cap. See proxy authentication methods.
Editorial note: Proxy providers change their pools, features and prices often, so treat any figures here as typical ranges at the time of writing and confirm current terms with the provider before you buy.