Every term you'll encounter when working with proxies - rotating, residential, sticky sessions, SOCKS5, CGNAT, and more. Plain definitions, no filler.
4
403 Forbidden
The server understood the request and refused it. In scraping it usually means the address class was rejected before anything else was considered.
429 Too Many Requests
The server accepted you and is asking you to slow down. What matters is what it counts against: an address, an account or a fingerprint.
A
Anonymous Proxy
A proxy that hides your real IP address but still signals to the target that a proxy is in use.
Anti-Bot System
Security software that detects and blocks automated traffic by scoring requests on IP, headers, fingerprint, and behavior signals.
ASN (Autonomous System Number)
A unique number identifying a network operator that controls a block of IP addresses on the internet.
B
C
CAPTCHA (in web scraping)
A challenge-response test sites use to distinguish human users from automated bots - frequently triggered by scraping activity.
CGNAT (Carrier-Grade NAT)
Carrier-Grade NAT is a technology mobile carriers use to share one public IP address among thousands of subscribers.
Concurrent Sessions (Threads)
The number of simultaneous connections or requests you can run through a proxy service at the same time.
D
Datacenter Proxy
A proxy hosted on servers in commercial datacenters, offering high speed and low cost per request.
Dedicated Proxy
A proxy IP assigned exclusively to one user - not shared with other customers.
DNS Leak
A privacy flaw where DNS lookups bypass your proxy, revealing which sites you visit to your ISP or a third party.
DNS Proxy
A server that takes your DNS queries, forwards them to a resolver and returns the answer, without carrying any of your actual traffic.
G
H
Headless Browser
A real web browser that runs without a graphical interface, controlled by code to load, render, and interact with pages.
Honeypot Trap
A hidden link, field, or page that real users never interact with, used to catch and flag automated bots that do.
HTTP CONNECT
The request a client sends to open a raw tunnel through a proxy. Everything after it is encrypted end to end, so the proxy forwards bytes it cannot read.
HTTP Proxy
A proxy that forwards HTTP and HTTPS requests between a client and a web server.
HTTP/2 Fingerprint
A signature built from how a client opens an HTTP/2 connection: its settings, window sizes, priorities and header order.
HTTPS Proxy
An HTTP proxy that supports the CONNECT method to tunnel encrypted HTTPS traffic between client and destination.
I
IP Address
A numeric label assigned to each device on a network, used to route traffic to and from it across the internet.
IP Ban
A block placed on a specific IP address, preventing it from accessing a website or service.
IP Geolocation Database
A vendor’s mapping from addresses to places. It is an estimate that different vendors make differently, and sites choose which one to believe.
IP Reputation
A judgement a site or a vendor makes about an address before it looks at your request. Mostly it is a judgement about the range, not about you.
IP Whitelisting
A rule that lets a service accept connections only from source addresses registered in advance. On a proxy it replaces the username and password.
IPv4 vs. IPv6 Proxies
IPv4 proxies use 32-bit addresses (the current standard). IPv6 proxies use 128-bit addresses - more abundant and often cheaper, but with limited site support.
IPv6 Proxy
A proxy that routes traffic through IPv6 addresses, offering enormous, cheap pools but limited to IPv6-compatible targets.
Is Web Scraping Legal?
Scraping publicly available data is generally lawful in many jurisdictions, but legality depends on the data type, site terms, and local law.
ISP Proxy
A static IP assigned by a real ISP but hosted on datacenter infrastructure - combining residential trust scores with datacenter performance.
P
Proxy Authentication
The method used to verify that a user is authorized to use a proxy endpoint - either username/password credentials or IP address whitelisting.
Proxy Bandwidth
The total amount of data (upload + download) transferred through a proxy connection, typically measured in GB.
Proxy Chaining
Routing traffic through two or more proxies in sequence, so each proxy only knows the previous and next hop, adding layers of anonymity.
Proxy Gateway
A single entry-point server that fronts a proxy provider's IP pool, assigning an IP to each connection from the pool behind it.
Proxy List
A collection of proxy IP addresses and ports, usually with credentials, formatted for import into scraping or automation tools.
Proxy Manager
Software that centralizes and automates proxy usage - rotation, routing rules, retries, and per-target configuration - across your pool.
Proxy Pool
A collection of proxy IP addresses managed by a provider, from which IPs are assigned to users for each request or session.
Proxy Port
The network port number on a proxy server that your client connects to, determining which protocol and gateway you use.
Proxy Pricing Models
The unit a provider charges in: a gigabyte, an address per month, a port or a day. Two providers can look equally priced and differ several times over on the same job.
Proxy Server
An intermediary server that sits between your device and the internet, forwarding your requests and returning responses under its own IP address.
Proxy vs VPN
A proxy reroutes traffic for a single app or request without encryption, while a VPN encrypts and reroutes all traffic from your device.
Public Proxy
A free, openly available proxy that anyone can connect to without authentication - typically slow, unreliable, and insecure.
R
Rate Limiting
A control that caps how many requests a single client or IP can make within a time window, returning errors once the limit is exceeded.
Request Headers
Key-value metadata sent with every HTTP request, describing the client, accepted content, and context of the request.
Residential Proxy
A proxy that routes traffic through IP addresses assigned by ISPs to residential internet connections.
Residential vs. Datacenter Proxies
Residential proxies use real ISP IPs with high trust scores. Datacenter proxies use server IPs that are faster and cheaper but more detectable.
Reverse Proxy
A server that sits in front of one or more web servers and forwards incoming client requests to them, hiding the backend from the client.
robots.txt
A file at the root of a site describing what its owner would prefer automated clients not to fetch. It is a convention, not an access control.
Rotating Proxy
A proxy that assigns a new IP address on each request or at a fixed interval.
S
Session Persistence
Keeping a sequence of requests recognisable as one visitor. It requires the client state and the exit address to stay together.
Shared vs Private Proxy
A shared proxy assigns the same IP to multiple users at once, while a private (dedicated) proxy gives one user exclusive use of the IP.
SOCKS4 vs SOCKS5
SOCKS4 and SOCKS5 are proxy protocols; SOCKS5 adds authentication, UDP support, IPv6, and remote DNS resolution over the older SOCKS4.
SOCKS5 Proxy
A proxy protocol that routes any TCP or UDP traffic - not just HTTP - through a proxy server, with authentication support.
SSL Proxy
A proxy that handles SSL/TLS-encrypted connections, either tunneling them intact or terminating and re-encrypting them for inspection.
Static vs Dynamic IP
A static IP stays the same over time, while a dynamic IP is reassigned periodically by the network.
Sticky Session
A proxy session that holds the same IP address for a defined time window rather than rotating on every request.
Structured Data Extraction
Reading the machine-readable blocks a page already publishes, instead of parsing the visible text with selectors.