IP Address, DNS, Proxy, VPN: 20 Networking Terms Explained in Plain English
Networking vocabulary has a way of leaking into everyday life. Your router's settings page talks about DNS and NAT, a streaming service blames your VPN, a website says your IP address has been rate limited, and a support agent asks whether you are behind a proxy. Most people nod along. Here are twenty of the terms that come up most often, grouped by what they do, each explained in plain English with an everyday comparison.
Addresses: how devices are identified
IP address. A number that identifies a device or a network connection on the internet, so data knows where to go. Think of it as a postal address for traffic. Every website you visit sees the IP address your request comes from.
IPv4 and IPv6. The two versions of IP addresses. IPv4 addresses look like 203.0.113.42 and ran out years ago because there are only about four billion of them. IPv6 addresses are much longer, written in hexadecimal with colons, and there are enough of them for every device imaginable.
Public and private IP address. Your home router has one public address that the internet sees, while the devices inside your home get private addresses that only make sense on your own network. It is the difference between a building's street address and the flat numbers inside.
Dynamic and static IP. A dynamic address is assigned by your provider and can change from time to time. A static address stays the same, which matters for things like running a server or being recognised by a workplace system.
NAT. Network Address Translation, the trick that lets many devices share one public address. Your router keeps track of which inside device asked for what and hands the answers back to the right one, like a receptionist forwarding calls.
CGNAT. Carrier grade NAT, the same idea on a much larger scale. Mobile networks and some broadband providers put thousands of customers behind a shared public address, which is why your phone's IP address is often shared with many strangers.
Names and routes: how traffic finds its way
DNS. The Domain Name System, the internet's phone book. It turns names like example.com into IP addresses that computers can use. When a site will not load but others do, a DNS problem is one of the usual suspects.
Resolver. The server that answers your DNS questions. Your provider runs one by default, but you can switch to a public resolver, which sometimes fixes loading problems or blocking at the provider level.
Router and gateway. The router moves traffic between networks. The gateway is the exit point from your network to the wider internet. At home, one small box usually does both jobs.
Latency, bandwidth and packet loss. Latency is how long data takes to make a round trip, measured in milliseconds. Bandwidth is how much data can travel at once. Packet loss is data that never arrives. A connection can have huge bandwidth and still feel sluggish because of high latency, the way a wide motorway can still have a long drive.
Middlemen: services that sit between you and a website
Proxy server. An intermediary that forwards your requests to websites on your behalf, so the site sees the proxy's address rather than yours. Businesses use a proxy server to check how their websites and prices appear in other countries, to collect public data without overloading one connection, and to test services from different locations. Unlike a VPN, a proxy usually applies to a single application, such as one browser, rather than the whole device.
VPN. A Virtual Private Network, an encrypted tunnel for all the traffic leaving your device. It hides what you are doing from the local network and your provider, which is why it is useful on public wifi. It moves your trust to the VPN company rather than making you anonymous.
CDN. A Content Delivery Network, a set of servers around the world that keep copies of a website's files close to visitors. It is why a site based on another continent can still load quickly for you.
Firewall. A filter that decides which traffic is allowed in or out, based on rules. Your router has one, your computer has one, and companies run much larger ones.
Tor. A network that routes traffic through several volunteer relays with layers of encryption, so no single relay knows both who you are and what you are visiting. It is designed for anonymity and is noticeably slower than a normal connection.
Location and access: why websites treat visitors differently
Geolocation. Estimating where a device is from its IP address. It is usually accurate to the country and far less reliable at city level, which is why an IP lookup sometimes places you in a town you have never visited.
Geoblocking. Restricting or changing content based on the visitor's country. It is the reason a video plays in one country and not another, and why shops show different prices and delivery options by location.
Rate limiting. A cap on how many requests a single address can make in a period of time. It protects websites from overload and abuse. If you refresh a page too many times, the error message you see is often this limit at work.
User agent. A short line of text your browser sends with each request describing itself, such as the browser name, version and operating system. Websites use it to serve a page that suits your device.
Terms that are often confused
- A proxy and a VPN both change the address a website sees, but a VPN encrypts all of the device's traffic while a proxy usually covers one application
- Bandwidth and speed are not the same thing, since latency often decides how fast a connection feels
- A public IP address identifies your network, not you personally, and linking it to a person requires records held by the provider
- DNS problems and connection problems look similar, but a DNS error means the name could not be found while a timeout means nothing answered
- Private browsing hides history on your device and does not change your IP address at all
Why the vocabulary matters
Knowing these terms turns vague frustration into a clear question. It is the difference between saying the internet is broken and saying the site times out on wifi but loads on mobile data, which any support team can work with. Most everyday network problems become much simpler once you know which part of the chain to look at.
FAQ
What is the difference between a proxy server and a VPN?
A proxy forwards requests for one application and changes the address a site sees. A VPN encrypts all traffic from the device through a tunnel.
Does my IP address show where I live?
It shows an approximate area, usually accurate to the country. Linking it to a person or a street requires records held by the internet provider.
Why does my IP address change?
Most home and mobile connections use dynamic addresses that providers reassign from time to time. Static addresses are a separate, usually paid, service.
What does DNS do?
It translates website names into the IP addresses that computers use to connect.
