What Is a CDN (Content Delivery Network)?

Q: What is a CDN (content delivery network) and how does it work?

A CDN is a network of servers spread across many locations that cache copies of a website so each visitor is served from somewhere nearby. Instead of every request reaching a single origin server far away, a nearby edge answers it, which makes pages load faster and reduces load on the origin. The CDN directs you to the closest edge and serves cached content from it.

Q: What is the difference between a CDN and a web host?

A web host is where the original, authoritative copy of a site lives, the origin, while a CDN is a caching and delivery layer that sits in front of the origin and distributes copies. The CDN does not replace the host, it accelerates and shields it. The origin holds the real content, and the CDN serves cached copies from nearby edges and fetches anything it cannot cache.

Q: What is an edge server in a CDN?

An edge server is one of the CDN machines located close to users that actually serves the cached content. A group of edge servers in one location is often called a point of presence, or PoP. The more locations a CDN has, the closer an edge is to any given visitor. Edge servers make a CDN fast because they hold content near the people requesting it.

Q: Does a CDN hide or change my IP address?

A CDN does not change your IP address, it changes the address the world sees for the website. Because a CDN is built from reverse proxies, a visitor sees the CDN edge IP while the origin server stays hidden behind it, which is why an IP lookup on many popular domains returns a CDN provider. To change your own visible address you would use a VPN, not a CDN.

Q: What is the difference between a CDN and a proxy server?

A CDN is a large distributed network of reverse proxies built to deliver a website fast by caching it near visitors, while a general proxy server is a single intermediary often used to change or hide a client address. A CDN represents and accelerates a server for everyone, whereas a forward proxy represents a client. They share the proxy idea but aim at opposite ends of the connection.

~/sheets/what-is-a-cdn.md

Delivering Websites From Close to You
A CDN, or Content Delivery Network, is a large set of servers spread across many locations that cache copies of a website so each visitor is served from somewhere physically near them. Instead of every request traveling to a single origin server that might be on the other side of the world, the CDN answers from a nearby location, which makes pages load faster and reduces load on the origin. Most large sites sit behind a CDN.
One practical effect: when you look up the IP address of a CDN-hosted domain, you see the CDN edge address serving you, not the origin server. You can observe this with our IP Lookup and trace how a name resolves with the DNS Lookup tool.
How a CDN Works
A CDN relies on two ideas: caching and proximity routing. Copies of a site content live on edge servers in many locations. When you request the site, the CDN directs you to a nearby edge, usually through DNS resolution or anycast routing that points you at the closest location. If that edge already has the content cached, it serves it immediately, and if not, it fetches it from the origin once and caches it for the next visitor. The shorter distance and the cache together are what cut the delay.
What Is an Edge Server?
An edge server is one of the CDN machines that sits at the edge of the network, close to users, and actually serves the cached content. The collection of edge servers in one location is often called a point of presence, or PoP. The more locations a CDN has, the closer an edge is likely to be to any given visitor. Edge servers are what make a CDN fast, because they hold the content near the people requesting it instead of forcing every request back to a central origin.
CDN vs Web Host
They do different jobs. A web host is where the original, authoritative copy of your site lives, the origin. A CDN is a caching and delivery layer that sits in front of that origin and distributes copies. The CDN does not replace the host, it accelerates and shields it. The origin still holds the real content, and the CDN serves cached copies of it from nearby edges and forwards anything it cannot cache back to the origin.
Does a CDN Change My IP Address?
A CDN does not change your IP address, it changes the address the world sees for the website. Because a CDN is built from reverse proxies, a visitor connecting to a CDN-fronted site sees the CDN edge IP, while the origin server address stays hidden behind it. That is why an IP lookup on many popular domains returns a CDN provider rather than the company own servers. If you want to change what the internet sees as your own address, a CDN is not the tool, a VPN is.
Frequently Asked Questions
What is a CDN (content delivery network) and how does it work?
A CDN is a network of servers spread across many locations that cache copies of a website so each visitor is served from somewhere nearby. Instead of every request reaching a single origin server far away, a nearby edge answers it, which makes pages load faster and reduces load on the origin. The CDN directs you to the closest edge and serves cached content from it.
What is the difference between a CDN and a web host?
A web host is where the original, authoritative copy of a site lives, the origin, while a CDN is a caching and delivery layer that sits in front of the origin and distributes copies. The CDN does not replace the host, it accelerates and shields it. The origin holds the real content, and the CDN serves cached copies from nearby edges and fetches anything it cannot cache.
What is an edge server in a CDN?
An edge server is one of the CDN machines located close to users that actually serves the cached content. A group of edge servers in one location is often called a point of presence, or PoP. The more locations a CDN has, the closer an edge is to any given visitor. Edge servers make a CDN fast because they hold content near the people requesting it.
Does a CDN hide or change my IP address?
A CDN does not change your IP address, it changes the address the world sees for the website. Because a CDN is built from reverse proxies, a visitor sees the CDN edge IP while the origin server stays hidden behind it, which is why an IP lookup on many popular domains returns a CDN provider. To change your own visible address you would use a VPN, not a CDN.
What is the difference between a CDN and a proxy server?
A CDN is a large distributed network of reverse proxies built to deliver a website fast by caching it near visitors, while a general proxy server is a single intermediary often used to change or hide a client address. A CDN represents and accelerates a server for everyone, whereas a forward proxy represents a client. They share the proxy idea but aim at opposite ends of the connection.
Last updated: April 2026