What is a CDN?

A Content Delivery Network(CDN), is a network of servers that deliver content. The purpose of the CDN is to cache and more quickly serve static content based on the geographical location between the origin server and the user making the request. This means when someone in Japan visits your website hosted in the United States, it will load just as fast as a website hosted in Japan.

The benefits of using a CDN are:

• Improved content availability and redundancy - High volume traffic or hardware failures can cause downtime for your website, a CDN distributes the load so your site can handle more traffic and endure hardware failure better than a single origin server.
• Improved load times - Users are served content from a Point of Presence(PoP) geographically closer to them than the origin server which means faster load times for your website.
• Increased security - A CDN can increase security by mitigating Distributed Denial-of-Service(DDoS) attacks, preventing vulnerability hacks and stopping brute force attempts against your website login pages and more.

Not all CDN are the same, some have a Zone URL and others have a Custom URL. The difference between them can be seen when viewing the source for your page, which are mostly aesthetic. The differences are:

• Zone URL CDN bundled with Managed WordPress Pro+.
  • A Zone URL CDN uses a default URL for cached content like images using the following structure:

      https://secureservercdn.net/ip_address/temp_domain/wp-content/uploads/year/month/image_name.jpeg       
    

    Example: https://secureservercdn.net/192.168.1.x/coolexample.com/wp-content/uploads/2019/06/qtq80-1024x380.jpeg
  • Zone URL CDN are less expensive to run maintain so are typically offered as a free or limited use addition to another product.
• Custom URL CDN bundled with Website Security Deluxe and Ultimate.
  • A Custom URL CDN will use the site's domain for cached content like images using the following structure:

      https://domain/wp-content/uploads/year/month/image_name.jpeg       
    

    Example: https://coolexample.com/wp-content/uploads/2019/06/qtq80-1024x380.jpeg
  • Custom URL CDN are usually a premium option or upgrade.

Whether you're using a Zone CDN or a Custom CDN to cache the static elements of your website, a CDN can improve your click through rates since slow loading websites are often abandoned before they load.

More Info

• CDN image indexing and Yoast SEO.