CDN is short for content delivery network. A content delivery network (CDN) is a system of distributed servers (network) that deliver pages and other Web content to a user, based on the geographic locations of the user, the origin of the web page and the content delivery server.
A Content Delivery Network (CDN) consists of two components: The Origin Server(s) – where the content to be distributed over Internet is originally stored & Cache Server(s) – where the content is duplicated. There is generally one Origin Server (either in the customer’s data center or in the cloud, with the content delivery network service provider – for example) and many cache servers (in multiple locations across the globe) so that, when a consumer is requesting a particular content on the Internet, it can be served by a cache server nearest to the consumer’s geographical location if the content is available there. Other wise, cache server fetches the content quickly from the origin server after protocol/route optimizations.
CDNs provide the following services
- Serving the content from the closest possible geographic location to minimize network latency.
- Replication (Caching) and deployment of large number of servers to minimize the server latency.
- Capacity On Demand.
- Monthly charges as per the content delivery (without high initial investments).
- Application Acceleration, Compression, Protocol optimization, etc.
- Route optimization (to identify and route traffic through the best/shortest/least congested route between origin server and cache servers.
- Static/ Dynamic/ Encrypted content optimization and faster delivery.
Free CDNs that have a Forever-Free Plan
- CloudFlare. CloudFlare is popularly known as the best free CDN for WordPress users.
- Photon by Jetpack
- AWS Cloudfront
- Google Cloud CDN
- Microsoft Azure CDN
The attached picture sows the basic pricing of Cloudflare services. Like this other CDNs also have their pricing.