CONTENT DELIVERY NETWORK

Delivering content
closer to everyone

A content delivery network (CDN) is a distributed system of servers that helps deliver web assets from locations closer to end users.

Explore how it works
Primary goal
Lower latency
Core technique
Edge caching
Typical assets
Images & scripts

01 / OVERVIEW

What does a CDN actually do?

When someone visits a website, a CDN can serve a cached copy of a requested asset from a nearby or well-connected edge location. Shorter network paths and fewer origin requests can make content delivery more efficient.

A

Faster asset delivery

Caching commonly requested files at the edge can reduce transfer time and improve the browsing experience.

B

Reduced origin traffic

Edge servers respond to eligible requests, lowering repeated traffic to the application or storage origin.

C

Controlled freshness

Cache policies, HTTP headers, and invalidation determine when visitors receive updated content.

02 / REQUEST FLOW

From browser to edge

  1. 01
    Request

    A browser requests an image, stylesheet, script, or another asset.

  2. 02
    Cache lookup

    The CDN checks whether an eligible, fresh copy is available at the edge.

  3. 03
    Response

    A cache hit is served immediately. On a miss, the CDN retrieves content from the origin.

03 / USE CASES

Where CDNs are useful

CDNs are widely used for images, video segments, JavaScript, CSS, fonts, downloadable files, and other frequently requested assets. Actual benefits depend on audience geography, network routes, traffic patterns, and caching strategy.

04 / FAQ

Common questions

Does a CDN replace web hosting?

Usually not. The origin remains responsible for the source content while the CDN helps distribute and cache eligible responses.

Will every website become faster?

Performance depends on the locations of users and edge servers, routing conditions, cache hit rates, and asset characteristics.

How are updated files delivered?

Cached copies expire according to cache policy or can be invalidated when the CDN supports purging.