ProxyHorizon Glossary
The Proxy & Networking Glossary
Plain-language definitions of the proxy, VPN, scraping and networking terms you'll run into — explained simply, with examples and use cases.
88 terms and counting
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Plain-language definitions of the proxy, VPN, scraping and networking terms you'll run into — explained simply, with examples and use cases.
88 terms and counting
An AI agent is an autonomous software program that uses artificial intelligence to make decisions and complete tasks on its own, such as browsing the web, gathering data, or taking actions toward a goal. It works with little or no step-by-step human guidance.
An anonymous proxy hides your real IP address from websites but still reveals that a proxy is being used.
An anti-detect browser lets you run many isolated browser profiles, each with its own fingerprint, cookies and proxy, so sites see them as separate, genuine users.
API integration is the process of connecting two or more software systems through their APIs so they can share data and trigger actions automatically. It lets apps work together without manual copying.
API scraping is collecting data by calling a website's underlying API endpoints directly instead of parsing its HTML pages. It is faster, cleaner, and more reliable than traditional scraping.
An ASN is a unique number assigned to a network (like an ISP or hosting company) that controls a block of IP addresses on the internet. It identifies who owns and routes a given range of IPs.
A backconnect proxy gives you one fixed gateway address that automatically rotates you through a large pool of changing IPs behind the scenes.
Bandwidth is the amount of data that can be transferred over a connection in a given time — and the most common way proxy and VPN usage is measured and billed.
Bot detection is the set of techniques websites use to tell automated traffic apart from real human visitors. It combines signals like IP reputation, fingerprints, and behavior to block scrapers and abuse.
Browser automation is the practice of controlling a web browser through code instead of manual clicks. It lets scripts navigate pages, fill forms, and extract data automatically.
Browser fingerprinting identifies and tracks a device by combining dozens of browser and system attributes — like fonts, canvas rendering and user agent — into a near-unique signature.
Browser isolation is a security technique that runs web browsing in a separate, sandboxed environment so that any malicious code never touches the user's real device. It keeps threats away from the local machine and network.
A browser profile is a saved set of browser data such as cookies, history, and fingerprint settings. In automation it isolates identities so each session looks like a distinct, consistent user.
Canvas fingerprinting is a tracking technique that uses the HTML5 Canvas API to draw hidden graphics and measure tiny rendering differences unique to your device. These differences form a stable identifier used to track and detect users.
A CAPTCHA is a challenge–response test used to tell humans and bots apart, such as identifying images or checking a box, to block automated access.
A CDN is a network of servers spread across the globe that stores copies of website content close to users for faster loading. It also protects sites by absorbing traffic spikes and filtering malicious requests.
CGNAT is a technique carriers use to share one public IP among many customers — which is exactly why mobile proxy IPs are so trusted and hard to block.
A Cloudflare challenge is a verification step that Cloudflare shows visitors it suspects are bots before allowing access to a site. It can range from an invisible check to an interactive puzzle.
Cookie management is the practice of storing, sending, and rotating browser cookies so a scraper can maintain logins and sessions across requests. Done well, it keeps automated traffic looking consistent and human.
Crawl budget is the number of pages a search engine or crawler will fetch from a site within a given time. It limits how much of a large website actually gets crawled and indexed.
Crawl rate is how fast a crawler sends requests to a website, usually measured in requests per second. Keeping it reasonable avoids overloading servers and triggering blocks.
Data extraction is the process of pulling specific information from a source, such as a web page, and turning it into structured, usable data. It is the core goal of web scraping.
A datacenter proxy is an IP address hosted on servers in a data center rather than assigned by an ISP — offering high speed and low cost, but easier for websites to detect.
A dedicated proxy is an IP address assigned exclusively to one user, so no one else shares the bandwidth or the IP's reputation.
DNS is the internet's phonebook — it translates human-readable domain names like example.com into the numeric IP addresses computers use to connect.
A DNS leak happens when your DNS lookups bypass your VPN or proxy and go to your ISP instead, revealing the sites you visit. It can undermine your privacy even when your traffic looks protected.
A headless browser is a real browser that runs without a visible interface, controlled by code — the workhorse for scraping JavaScript-heavy sites and automation.
A honeypot trap is a hidden element or decoy placed on a website to catch bots. Real users never interact with it, so any request that touches it is flagged as automated.
HTTP headers are small pieces of metadata sent with every web request and response, describing things like the browser, content type, and cookies. They quietly shape how servers treat your traffic.
An HTTP proxy is an intermediary server that forwards web (HTTP/HTTPS) requests on your behalf, able to read, cache and filter traffic at the application layer.
HTTP/2 is the second major version of the HTTP protocol that loads web pages faster by sending many requests over one connection at the same time. It replaced the older, slower one-request-at-a-time model of HTTP/1.1.
HTTP/3 is the newest version of HTTP that runs over the QUIC protocol on UDP instead of TCP. This makes connections faster and more resilient, especially on mobile and unstable networks.
HTTPS is the secure version of HTTP that encrypts data between your browser and a website using SSL/TLS. It prevents eavesdroppers from reading or tampering with the traffic.
IKEv2 is a fast, stable VPN protocol that is especially good at keeping your connection alive when you switch networks. It is commonly used on mobile devices for its speed and reliability.
IP reputation is a trust score that websites and security systems assign to an IP address based on its past behavior. A clean IP is trusted, while a flagged one may be blocked or challenged.
IP rotation is the practice of automatically cycling through multiple IP addresses so that successive requests originate from different IPs.
IP whitelisting is a security method that only lets pre-approved IP addresses connect to a service, blocking everyone else by default.
IPv4 is the fourth and most widely used version of the Internet Protocol, giving every connected device a numeric address like 192.168.1.1. It supports about 4.3 billion unique addresses.
IPv6 is the newest version of the Internet Protocol, created to replace IPv4 because the world ran out of addresses. It offers a virtually unlimited supply of unique IP addresses.
An ISP proxy (static residential) is a datacenter-hosted IP that is registered to an Internet Service Provider, combining datacenter speed with residential-level trust.
MCP (Model Context Protocol) is an open standard that lets AI applications connect to external tools, data sources and services through one consistent client–server interface.
A mobile proxy routes traffic through real 3G/4G/5G cellular connections, using carrier-assigned IPs that are the hardest of all proxy types to detect or block.
A multi-hop VPN routes your traffic through two or more VPN servers instead of one, encrypting it multiple times. This adds an extra layer of privacy by making your connection harder to trace.
An obfuscated VPN disguises your VPN traffic so it looks like ordinary HTTPS web traffic. This helps you bypass firewalls and censorship that block standard VPN connections.
OpenVPN is a popular open-source VPN protocol that creates a secure, encrypted tunnel between your device and a server. It is trusted for being highly secure, configurable, and widely supported.
Playwright is an open-source browser automation framework from Microsoft that controls Chromium, Firefox, and WebKit. It is widely used for testing and JavaScript-heavy web scraping.
A port number is a numeric label that directs network traffic to the right program on a device. Combined with an IP address, it tells data exactly where to go.
A private proxy is an IP address dedicated to a single user, giving you exclusive use, full bandwidth, and a reputation no one else can spoil.
Proxy authentication is the process of proving you are allowed to use a proxy, usually with a username and password or by approving your IP address in advance.
A proxy pool is a collection of many proxy IP addresses that a tool rotates through to spread requests and avoid getting blocked.
A proxy server is an intermediary computer that sits between your device and the internet, forwarding your requests so that websites see the proxy's IP address instead of your own.
Puppeteer is a Node.js library by Google that controls Chrome and Chromium through the DevTools Protocol. It is popular for scraping JavaScript-rendered pages and automating Chrome tasks.
Rate limiting restricts how many requests a client can make in a given time, and it is one of the most common defenses scrapers must work around.
A remote browser runs in the cloud or on a remote server rather than your local machine, controlled over the network. It is used for scalable automation, scraping, and isolation.
Request throttling is deliberately slowing down how often a scraper sends requests so it stays under a site's limits. It helps avoid bans, server overload, and detection.
A residential proxy routes your traffic through a real device with an IP assigned by an Internet Service Provider, so requests appear to come from a genuine home user rather than a server.
A reverse proxy sits in front of one or more servers and forwards client requests to them, handling load balancing, caching, TLS termination and security on the servers' behalf.
Robots.txt is a simple text file at the root of a website that tells crawlers and bots which pages they may or may not access. It is a voluntary set of rules, not a technical lock.
A rotating proxy automatically assigns a different IP address from a pool for each request or on a set interval, spreading traffic across many IPs to avoid blocks.
Robotic Process Automation (RPA) uses software "bots" to mimic the repetitive clicks, typing, and steps a human performs in apps and websites. It automates routine digital tasks without changing the underlying systems.
Selenium is a long-established browser automation framework that controls real browsers through the WebDriver standard. It supports many languages and is widely used for testing and scraping.
A session cookie is a temporary cookie a website uses to remember you during a single visit, such as keeping you logged in. It is deleted when you close the browser or the session ends.
Shadowsocks is an open-source encrypted proxy designed to bypass internet censorship. It disguises traffic to slip past firewalls that block traditional VPNs.
A shared proxy is a proxy server whose IP address is used by multiple people at the same time, splitting the cost and bandwidth among everyone.
SOCKS5 is the latest version of the SOCKS proxy protocol. It routes any kind of network traffic — TCP and UDP — between a client and a server through a proxy, with optional authentication and no awareness of the underlying application.
Split tunneling is a VPN feature that lets you route some of your traffic through the encrypted VPN tunnel while other traffic goes directly to the internet. This gives you control over which apps or sites use the VPN.
An SSH tunnel uses the secure SSH protocol to encrypt and forward traffic between your device and a remote server. It is a simple way to secure connections or bypass network restrictions.
SSL/TLS is the encryption protocol that secures data in transit on the web — the 'S' in HTTPS — protecting it from eavesdropping and tampering.
A sticky session keeps the same proxy IP for a set period, so multi-step workflows like logging in and checking out stay on one consistent address.
A subnet is a smaller network carved out of a larger IP address range, grouping related addresses together. It helps organize and route traffic efficiently.
TCP/IP is the core set of rules that lets computers find each other and exchange data reliably across the internet. It combines IP for addressing and routing with TCP for ordered, error-checked delivery.
TLS fingerprinting identifies a client by analyzing the details of how it negotiates an encrypted connection. It lets servers detect specific tools or browsers before any web request data is exchanged.
A transparent proxy intercepts your traffic without hiding your IP address, and often without you even knowing it is there.
UDP (User Datagram Protocol) is a fast, connectionless way to send data over the internet without guaranteeing delivery or order. It trades reliability for low latency, making it ideal for streaming and real-time apps.
A user agent is the identifying string a browser sends with every request, telling the server which browser, version and operating system you are using.
Web scraping is the automated extraction of data from websites — fetching pages programmatically and parsing their content into structured data.
A webhook is an automated message sent from one app to another the moment an event happens. Instead of constantly asking for updates, your app gets notified instantly.
A WebRTC leak exposes your real IP address through the browser's built-in real-time communication feature — even when you are using a VPN or proxy.
WebSocket is a protocol that opens a persistent, two-way connection between a browser and a server. Unlike normal HTTP requests, it lets data flow in both directions continuously without re-connecting each time.
WireGuard is a modern, fast and lightweight VPN protocol known for its tiny codebase, strong cryptography and excellent performance.