Proxy glossary: every term, explained
40+ plain-English definitions of the proxy terms you'll meet while shopping, scraping and configuring. Bookmark it.
A
Anti-bot system
Software that detects and blocks automated traffic by analysing IP reputation, request patterns, headers and browser fingerprints. The reason residential and mobile proxies exist.
ASN targeting
Selecting proxy IPs by Autonomous System Number — essentially the specific network operator they belong to. Useful for very precise geo- and carrier-level targeting.
Authentication
How a provider verifies it's really you connecting, either via username and password or by IP whitelisting.
B
Backconnect proxy
A single gateway endpoint that automatically routes each request through a different IP from a large pool, so you don't manage individual IPs yourself.
Bandwidth
The volume of data transferred through a proxy, usually measured in gigabytes. Residential and mobile proxies are typically billed by bandwidth.
Ban
When a website blocks an IP or account from accessing it, usually after detecting automated or abusive behaviour. See our guide to avoiding bans.
C
CAPTCHA
A challenge (like identifying images) used to tell humans from bots. Frequent CAPTCHAs signal that your traffic looks automated.
CGNAT (Carrier-Grade NAT)
The technique mobile carriers use to share a few public IPs among many subscribers. It's why mobile proxies are so hard to block.
Concurrency
The number of simultaneous connections you can run at once. Higher concurrency means faster large-scale jobs.
Cookie
A small piece of data a site stores in your client to track sessions. Persisting cookies correctly helps you look like a returning human user.
D
Datacenter proxy
A proxy whose IP is hosted on commercial server infrastructure. Fast and cheap, but easier to detect. See datacenter vs residential.
Dedicated (private) proxy
A proxy IP assigned to you alone, giving you full control of its reputation and performance — for a higher price than shared proxies.
E
Endpoint
The host address and port you connect to in order to use a proxy, e.g. gate.example.com:8080.
F
Fingerprint (browser fingerprint)
The unique combination of browser signals — canvas, fonts, timezone, screen size — that sites use to identify a client even without cookies.
Forward proxy
The standard proxy that sits between a client and the internet, forwarding the client's requests outward. The opposite of a reverse proxy.
G
Geo-targeting
Choosing proxy IPs in a specific country, region or city so you appear to browse from that location and see localised content.
Gateway
A single proxy entry point that distributes your traffic across a pool of IPs behind it. See also backconnect proxy.
H
HTTP/HTTPS proxy
A proxy built for web traffic. HTTPS proxies add encryption. The default choice for browsing and web scraping.
Headers
Metadata sent with each web request (such as User-Agent and accept-language). Realistic, consistent headers help avoid detection.
I
IP address
The numerical label identifying a device on the internet. Proxies swap your real IP for one of theirs.
IP rotation
Automatically changing the IP used for requests — per request or per interval — to spread traffic and avoid rate limits.
ISP proxy (static residential)
A residential IP hosted on data-center hardware, combining residential trust with datacenter speed and a fixed IP. See types of proxies.
IP whitelisting
Authorising your own IP address so you can use a proxy without a username and password. Convenient for fixed servers.
L
Latency
The delay between sending a request and receiving a response. Datacenter and ISP proxies have the lowest latency.
M
Mobile proxy
A proxy that routes through a real 4G/5G cellular network. The highest-trust, hardest-to-block — and most expensive — type.
P
Pool (IP pool)
The total set of IP addresses a provider can route your traffic through. Bigger, cleaner pools mean fewer blocks.
Port
A numbered channel on the proxy endpoint. Different ports can select different behaviours, like rotating vs sticky sessions.
Proxy server
An intermediary server that forwards your requests to websites on your behalf, hiding your real IP. The core concept behind everything here.
R
Rate limit
A cap a site places on how many requests an IP can make in a time window. Proxies spread requests to stay under these limits.
Residential proxy
A proxy using an IP that an ISP assigned to a real home. The most trusted everyday type. See residential proxies explained.
Reverse proxy
A proxy that sits in front of servers (not clients), handling incoming traffic for load balancing, caching or security. The opposite of a forward proxy.
Rotating proxy
A proxy that assigns a new IP per request or interval — ideal for large-scale scraping.
S
Session
A continuous interaction with a site. Sticky sessions keep one IP for the session's duration.
Shared proxy
A proxy IP used by multiple customers at once. Cheaper, but you share its reputation and bandwidth.
SOCKS5
A flexible, lower-level proxy protocol that forwards any kind of traffic — web, email, P2P, gaming — without interpreting it.
Static (sticky) proxy
A proxy that keeps the same IP for a set period, essential for logins and multi-step flows.
Success rate
The percentage of requests that return clean data without being blocked — a key quality metric in our testing.
Subnet
A block of related IP addresses. Datacenter proxies often share subnets, which makes them easier to identify.
T
Throttling
Deliberately slowing your request rate to mimic human behaviour and avoid triggering anti-bot defences.
U
Uptime
The percentage of time a proxy network is available and working. Top providers measure 99.9% or higher.
User-Agent
A header identifying the browser and device making a request. Realistic, rotating User-Agents help avoid detection.
W
Web scraping
The automated collection of public data from websites — the most common use of proxies. See our complete scraping guide.
Whitelisting
See IP whitelisting — authorising a trusted IP to use a proxy without credentials.
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