Proxy Glossary: What Do Proxy Terms Mean?

A proxy glossary defines the terms you meet when choosing, configuring and debugging proxies, all on one page. The difference between residential and datacenter, how long a sticky session lasts, why a 407 error appears and what socks5h does are all answered in the categories below.

The terms are grouped under six headings: proxy types, protocols, sessions and rotation, authentication, errors and diagnostics, and network and location. Package and billing terms come last. Within each heading the terms are in alphabetical order; each definition is one to three sentences and links to the relevant product, tool or guide where useful.

If proxies are new to you, read what is a proxy first. The package table on this page shows the three products that come up most often in this glossary.

Proxy types: what do residential, datacenter, ISP and mobile mean?

Anonymous proxy — A proxy that does not pass your IP address to the target site. An "elite" or high-anonymity proxy also leaves out headers such as Via or X-Forwarded-For that reveal proxy use.

Datacenter proxy — A proxy whose IP address belongs to a data center or hosting company. It is fast and high-capacity; target sites can recognize these IP ranges easily through their ASN. At WeProxy, Rotating Datacenter IPv4 offers 10M+ IPv4 addresses with ASN and city targeting.

Dedicated proxy — An IP address assigned only to you for a set period. Because no other customer shares it, the IP's history depends on your own use.

Forward proxy — A proxy that sits in front of the client and sends requests to the outside world on the client's behalf. All commercial proxy services work on this model.

ISP proxy — A static IP registered to an internet service provider but hosted on data center infrastructure. It combines a residential trust profile with data center stability. WeProxy's Static ISP IPv4 Proxy is offered in the US with sessions of up to 30 days.

Mobile proxy — A proxy that exits through 4G/5G mobile carrier IPs. On mobile networks many users share one IP, so these IPs are preferred for social platforms and ad verification. The real-SIM mobile proxy supports HTTP only; check the product page for availability.

Residential proxy — A proxy that exits through ISP-issued IP addresses assigned to home internet connections. WeProxy residential addresses come from a consent-based SDK partner program in which participants opt in knowingly, get paid and can leave at any time. The Rotating Residential IPv4 pool contains 100M+ IPs.

Reverse proxy — A proxy that sits in front of a server and receives incoming requests. It is used for load balancing, caching and TLS termination; it is not the kind of proxy used to change your IP.

Shared proxy — A model in which several users use the same IP address at the same time. It lowers cost, but other users' behavior can affect the IP's reputation.

Transparent proxy — A proxy that intercepts traffic without client configuration and usually forwards the original IP in headers. It is common in corporate networks and carrier infrastructure.

Proxy types at a glance:

For the differences between types with use cases, see the residential vs mobile vs datacenter vs ISP proxy comparison.

Protocol terms: what are HTTP, SOCKS5 and UDP?

CONNECT method — The HTTP method a client uses to ask an HTTP proxy to open a TCP tunnel to the target server. When you reach HTTPS sites through an HTTP proxy, TLS traffic passes through this tunnel encrypted; the proxy cannot see the content.

HTTP proxy — A proxy that understands and forwards HTTP requests. It forwards plain HTTP requests directly and builds a CONNECT tunnel for HTTPS. If authentication fails, it returns 407.

HTTPS proxy — In everyday use, an HTTP proxy that can carry HTTPS sites through a CONNECT tunnel. Technically it can also mean a proxy where the connection between client and proxy is itself TLS-encrypted; check your tool's documentation for which one it expects.

SOCKS5 — A proxy protocol that works independently of the application protocol and forwards TCP connections and, optionally, UDP traffic (RFC 1928). It does not read or modify HTTP headers. For details, see the SOCKS5 proxies page.

socks5h — A scheme name in curl and many libraries that makes DNS resolution happen on the proxy side instead of the client. It stops local DNS queries from leaking the target domain.

UDP — A transport protocol that sends data without setting up a connection. Games, voice calls and real-time applications use UDP; an HTTP proxy cannot carry UDP.

UDP ASSOCIATE — The SOCKS5 command used to relay UDP traffic through the proxy. At WeProxy it is available only on Static Residential IPv4 in locations outside Türkiye; Türkiye static residential IPs (Türk Telekom and Vodafone networks) support HTTP and SOCKS5, without UDP.

To see both protocols side by side, read the HTTP vs SOCKS5 comparison.

Session and rotation terms: what do sticky and rotating mean?

Gateway — The entry point that receives all your requests and picks an exit IP from the pool. The WeProxy gateway address is gw.weproxy.com.tr:8989; the exit IP is chosen in the background based on your country and session settings.

IP pool — The full set of addresses a rotating product can pick an exit IP from. The larger the pool, the lower the chance that the same IP shows up on the same target again.

Rotating proxy — A proxy that uses a different exit IP on every request or at set intervals. It is used for scraping and price monitoring, where many independent requests are sent. Details are on the rotating proxies page.

Rotation interval — How often the exit IP changes on a rotating connection. It can change on every request or be tied to a time window; on Rotating IPv6 the IP changes on every request in Datacenter packages and at least every 120 seconds in Residential packages.

Session ID — An identifier added to the username that keeps the same exit IP for a while. At WeProxy the same IP can be held for up to 24 hours in the residential pool and up to 60 minutes in the mobile pool.

Static IP — An exit IP that does not change for the purchased period. It suits account management, systems that require an IP allowlist and long sessions.

Sticky session — A session that uses the same exit IP from a rotating pool for a set time. It prevents the IP from changing midway through logged-in flows and multi-step actions such as a checkout. To choose between them, see the sticky vs rotating proxy guide.

Authentication terms: IP whitelist and username/password

IP whitelist — Accepting proxy connections only from IP addresses you registered in advance. It is handy for tools that cannot send a username and password; if your server's IP changes, you need to update the list.

Proxy-Authorization — The request header that carries credentials to an HTTP proxy. When it is missing or wrong, the proxy responds with 407 Proxy Authentication Required.

Proxy string — Connection details written on one line, for example http://USER:[email protected]:8989. Tools may expect a different order (such as host:port:user:pass); use the proxy format converter to switch between them.

Username and password — Authentication by sending credentials with every connection. At WeProxy, username/password and IP whitelist work on all packages over both HTTP and SOCKS5.

Error and diagnostic terms: what do 407, 429 and timeout mean?

403 Forbidden — The target site refused the request. It usually happens because of IP type, IP reputation, a country restriction or the browser fingerprint; the proxy connection itself works.

407 Proxy Authentication Required — The proxy did not accept your authentication. Check the username, password, URL encoding of special characters or the IP whitelist entry.

429 Too Many Requests — The target site reports that it received too many requests in a short time. Typical fixes are lowering the request rate, respecting the Retry-After header and rotating more often.

502 Bad Gateway — The proxy did not get a valid response from the target server. The target may be down, may have dropped the connection, or the exit IP may not reach it at that moment.

504 Gateway Timeout — The proxy did not get a response from the target server within the time limit. On slow targets, raise the timeout or retry the request with a new IP. For all codes, see the proxy error codes guide.

Block rate — The share of requests that end in a block, a CAPTCHA or an error page. IP type, request rate and fingerprint consistency set this rate together.

CAPTCHA — A test a target site shows to check whether the requester is human. Frequent CAPTCHAs mean the IP type or request behavior looks suspicious to the target.

DNS leak — Domain lookups going through your local DNS server while traffic exits through the proxy. It is prevented with socks5h or proxy-side DNS resolution; details are in the DNS leak guide.

Fingerprint — A device signature derived from browser, operating system, screen, fonts and TLS settings. If the fingerprint stays the same while the IP changes, the target site can link the sessions.

p0f — A passive fingerprinting method that guesses the operating system from TCP/IP packet characteristics. Static Residential IPv4 includes p0f OS spoofing.

Timeout — A connection or response not completing within the set time. It can happen while connecting to the proxy, connecting to the target or reading the response; knowing which stage failed shortens diagnosis.

WebRTC leak — The browser exposing your real local or public IP address to a site through WebRTC. It happens independently of proxy settings and is closed with a browser setting or an extension.

To quickly check whether a proxy works, its latency and its exit IP, use the proxy checker.

Network and location terms: ASN, CGNAT and geo-targeting

ASN (Autonomous System Number) — A number assigned to the organization that runs a network. Target sites use the ASN to tell whether an IP belongs to a home ISP, a mobile carrier or a data center; in some locations you can target at the ASN level.

CGNAT (Carrier-Grade NAT) — A method in which a carrier places many subscribers behind the same public IPv4 address. It is common on mobile networks, which is why blocking a single mobile IP can affect many real users.

Exit IP — The IP address through which the proxy reaches the internet and which the target site sees. Check your exit IP with the my IP tool and an IP's country and ASN with the IP lookup tool.

Geo-targeting — Selecting the exit IP from a specific country, city or ZIP code. WeProxy residential and mobile pools support country and city targeting; see the geo-targeting guide and the locations page.

IPv4 — The 32-bit internet addressing system with roughly 4.3 billion addresses. Since almost every site is reachable over IPv4, most proxy products use it.

IPv6 — The 128-bit addressing system with a far larger address space. An IPv6 proxy can only reach targets that support IPv6; check a target with the IPv6 checker. For the differences, see IPv4 vs IPv6.

ISP (internet service provider) — The company that provides internet access to subscribers. Which ISP an IP is registered to is one of the signals that affects how much target sites trust that IP.

Latency — The time it takes for a request to reach the target and the response to return, usually measured in milliseconds. Physical distance between proxy and target and the network type affect latency directly.

Package and billing terms: GB, port and threads

Bandwidth — The amount of data passing through the proxy. At WeProxy, usage is measured as the sum of sent and received traffic.

Concurrent sessions (threads) — The number of connections kept open at the same time. Rotating residential and datacenter products have no thread limit; the Rotating IPv6 product page states support for up to 1,000 concurrent requests.

Free trial — A way to test the network before buying. Premium Rotating Residential comes with a 1 GB free trial.

Pay per GB — Billing based on the amount of traffic you use. It applies to rotating residential, datacenter and mobile products; purchased GB never expire, stay in your balance until used and do not reset monthly.

Port — The numbered entry point on the proxy server where the connection is made. Some packages are billed monthly per port; Rotating IPv6 and unlimited residential packages, for example, are port-based and have no bandwidth limit.

Unlimited traffic — No GB limit during the package period. Static residential IPs include unlimited traffic per IP; the practical limit is the capacity of your own infrastructure.

How do you choose the right proxy with these terms?

The terms in this glossary map to the questions you should ask when choosing a proxy product. Go through them in this order:

1. Define the target. Which site or app, seen from which country and city? This sets the IP type and the geo-targeting you need.
2. Pick the IP type. Datacenter for high-volume, speed-sensitive work; residential or ISP where trust signals matter; mobile IPs for mobile app and social platform testing.
3. Decide the session model. Rotating for independent requests, sticky sessions for logged-in flows, a static IP if you need the same IP for months.
4. Check the protocol. HTTP is enough for browsers and scraping; non-HTTP traffic needs SOCKS5, and UDP needs a product with SOCKS5 UDP ASSOCIATE.
5. Choose the authentication method. IP whitelist if you work from a fixed server, username and password in changing environments.
6. Match billing to your traffic. Pay per GB for variable volume, monthly per port or per IP packages for steady, high volume.
7. Test after buying. Check the exit IP, country and latency; follow the target site's rules and the acceptable use policy.

Prices and package options are on the pricing page and in the package table on this page.

Frequently asked questions

What is the difference between a sticky session and a rotating proxy?

A rotating proxy uses a different exit IP on every request or at set intervals, which suits large numbers of independent requests. A sticky session keeps the same IP for a set time and stops it from changing midway through logged-in, multi-step flows. At WeProxy you add a session ID to the username to keep the same IP for up to 24 hours in the residential pool and up to 60 minutes in the mobile pool.

What is the difference between residential and datacenter proxies?

Residential proxies use ISP-issued IPs assigned to home internet connections, so target sites see them as ordinary user traffic. Datacenter proxies use data center IPs; they are faster and suit high-volume work, but they are easy to recognize through their ASN. The choice depends on how sensitive the target site is to IP type and on the volume of your work.

What is the difference between SOCKS5 and an HTTP proxy?

An HTTP proxy carries only HTTP and HTTPS traffic and uses a CONNECT tunnel for HTTPS. SOCKS5 is protocol-independent; it relays TCP connections and, on products that support it, UDP traffic. Both work for browsers and scraping. Game clients, email or custom application traffic need SOCKS5. Rotating residential, datacenter and static residential products support both protocols.

Should I use IP whitelist or username and password?

If you work from a fixed server or office connection, IP whitelist is practical because you do not keep credentials in your code. If your IP changes, you connect from several machines or you run in the cloud, username and password are more flexible. At WeProxy both methods work on all packages over HTTP and SOCKS5; settings such as the session ID are passed through the username.

Why do I get a 407 error when using a proxy?

407 Proxy Authentication Required means the proxy did not accept your credentials. The most common causes are a wrong username or password, special characters in the password that are not URL-encoded, connecting from an address that is not on the IP whitelist, and a tool that does not send the Proxy-Authorization header. For all error codes, see the proxy error codes guide.

What is the difference between pay per GB and pay per port?

With pay per GB you pay for the traffic you use, and purchased GB never expire and stay in your balance until used. It suits variable or low-volume work. Monthly per-port packages have no bandwidth limit and the cost does not depend on traffic, which makes them more predictable for continuous, high-volume work. Rotating IPv6 and unlimited residential packages are port-based.