Almost all of us enjoy the benefit of a Content Delivery Network, whether we realize it or not. Content Delivery Networks (CDN) also referred as Content Distribution Networks is what you call a system of network hardware containing copies of data located in various geographical locations, depending on the local demand from clients requesting the resources.

Content delivery networks are especially useful for delivering rich media content to users from different geographical locations, avoiding delay and bandwidth overload near the main server. CDNs can contain all types of data, but most often they are used to distribute data which demands high bandwidth. A few rough examples are downloadable software, media files and documentations, multimedia streams, online games as well as database queries, etc.

Some of the most popular sites on the Internet depend on content delivery networks. One of the simplest examples is Google. They have a network of data centers, able to return results to your search query in only a fraction of a second. They wouldn't be able to accommodate the need of everyone around the globe if it wasn't for they network of mutually linked data centers which are able to distribute the the demand for their service.

Apart from the in-house solutions, content distribution networks operating on the same principal are widely available for everyone. Smaller businesses without the resource to build their own CDN can take advantage of commercial services such as Limelight Networks.

There is hardly a Internet user who hasn't used P2P services before. P2P networks are a valid representative of content delivery networks. Most of the times they are a lot less expensive to operate and depend mostly on user contribution and demand. The strong side of P2P is the more users download the content the more efficient it becomes for the P2P owner, utilizing the bandwidth of every client.