CDN (content delivery network)
Also known as: content delivery network, what is a CDN, edge server
A CDN (content delivery network) is a network of servers spread around the world that store copies of files — images, video, app updates — close to users, so content loads from a nearby server instead of a distant origin. It speeds up downloads without changing how much storage the file uses on your device.
- Serves files from a server geographically near you
- Speeds downloads by cutting distance and latency
- Caches on the network, not on your device’s storage
How a CDN speeds delivery
Instead of every user fetching a file from one central origin server, a CDN caches copies on edge servers in many regions. When you load a page or download an app update, the content comes from the edge server nearest you, which cuts distance and latency.
This is why large downloads — operating-system updates, streaming video, big app installs — often arrive quickly: they are served from a nearby CDN node rather than a single faraway data center.
CDN vs your device cache
A CDN cache lives on the network, not on your phone, so it does not consume your device storage. The copy that ends up taking space locally is whatever your app or browser saves after the download — its own cache or downloaded files.
In short, a CDN affects how fast content reaches you, while on-device caches and downloads affect how much space it occupies once it arrives.