What is a Content Delivery Network: A brief Overview of CDN


By Ann Oliver

Do you own a website that experiences massive clicks around the world daily? When today’s advanced websites serve loads of videos, high-end animations, and images, these large media files can significantly slow down the site unless you employ a CDN (Content Delivery Network) to optimise the delivery process. 

Are you a newbie searching for what is a Content Delivery Network? CDNs are imperative when you require your site to run and perform smoothly and serve more people. 

To help you get in-depth knowledge about this widely adopted service, I have come up to cover it comprehensively. 

Introduction to CDN

CDN, the most buzzing word of today’s extremely competitive digital world, is essentially a highly engineered and worldwide spread combination of proxy servers that intend to accelerate a website’s asset delivery process by cutting loading delay and latency. 

The primary purpose of a CDN is to bring the end-users and website resources closer for prompt delivery and improved browsing quality coupled with a more satisfying user experience. 

CDNs mainly optimise static content (Sometimes also dynamic content) delivery. 

Website static assets are:

  • Video
  • Pictures
  • HTML pages
  • JavaScript files
  • Style sheets, etc. 

Any site (B2B or B2C) or mobile application that experiences massive traffic load or has international users can employ a CDN and boost performance. 

How Does CDN Caching Work?

Caching is the process of storing your website resources temporarily in CDN servers for subsequent uses, thus optimising delivery.

Let’s get in-depth how CDN caching works:

  • CDNs cache and store a site’s static resources in its distributed caching servers positioned in multiple locations worldwide.
  • When you integrate a CDN with your website and receive a page access request from any corner of the world, the request doesn’t have to travel a long way to hit the origin server.
  • Instead, a CDN ensures the access request follows the shortest route and the page gets delivered by the visitor’s closest CDN PoP.
  • The CDN server has that page or content already cached. So it can speed up the delivery process, limiting the gap between the visitor and the demanded resource. 
  • Once the CDN server is hit by request, it can scale that request, point out the requested data, and convey it to the target visitor through caching.

CDN vs. Web Hosting: The Differences

Don’t misinterpret CDN, considering it acts as a hosting service. CDN doesn’t host a site. As I have already stated, CDN is a specialised service that speeds up a site and boosts its performance while running concurrently with the hosting server

The differences are:

  • A hosting/origin server hosts your website. On the other hand, a CDN can handle your asset delivery process more efficiently.
  • While host servers save the original files of a site, CDN distributes them among its PoPs after caching.
  • As the hosting server hosts and serves the content from a single platform, the delivery process may encounter a larger loading delay. CDNs improve load time by conveying content from the nearest PoP. 
Web hosting and data centre

Why is CDN Essential

CDN, with its top-notch functionalities, offer immense benefits:

CDN Reduces Hosting Cost

As your origin server handles limited content requests and data transfer, you will be utilising less bandwidth, resulting in lessened bandwidth cost. 

Boosted Customer Experience

When even a 1-second loading delay can reduce a website’s pageview by 11%, a speedy and high-performance site is a must for offering quality browsing. A CDN ensures quicker page loading even if your site is loaded with media files by optimising them with compression or resizing, resulting in speedy delivery and better viewing.

Provision of Content Before Clicking

CDNs are high-performance systems that can analyse and evaluate your website visitors’ behavior and use high-end probability algorithms to predict their future searches for better performance

Keep Your Site Always Available

If you require to keep your website always available, ensuring no downtimes or slowness even during traffic spikes, employ a CDN service. CDNs serve users from their most adjacent data centers. So they can manage traffic load better than the origin server, ensuring your site and content are always up. 

Search Engine Optimisation (SEO) Perk

Search engines, especially Google, hate slow sites. No matter how much quality content you upload. If the site loads slowly, it will be ranked lower than faster sites by Google. 

CDNs (Content Delivery networks) deliver optimised images by ensuring your images index as quickly as possible, and Google crawls them more frequently, boosting your SEO ranking. 

What to Search For In a CDN Provider

Are you in a hassle thinking about which CDN will match your specific need and how you can pick the most suitable one? Go through the following checklist to make the best decision:

  • Immediate Support in Case of Emergency: When a fraction of minutes in network malfunctioning can cause a huge loss, you would never want to wait for your CDN support team to respond to your message in an emergency, right? Evaluate how expert and prompt assistance a CDN provider provides and go with one that comes with phone and ticket support, live chat, etc. 
  • Free Trial Period to Test Speed: If you want to select a more robust and powerful CDN network, try out the free trials offered by various CDN providers and evaluate their network speed. Though speed depends on different factors, using the free trials will help you understand the robustness of the CDN infrastructure better. 
  • Geographic Coverage: Before picking a CDN, make sure it can offer coverage to your target region. 
  • Development Scope: You are spending a handsome amount on employing a CDN to keep your website updated and make it perform optimally, right? Check if the CDN you have decided to integrate has enough development scope, evolves with time to add new features, and allows you to use them. 
  • Network Security: It is another crucial criterion you cannot overlook. Choose a CDN provider that fights layer 3 and 4 DDoS attacks, offers top-notch security to the network infrastructure with WAF, SSL/TLS encryption, etc. 

Limitations of CDN Providers

  • Delivering content through a third-party service means you lose some control.
  • Employing a CDN can add complexity to website management.
  • A CDN will add to your expenses.