With the growing need for fast websites (thanks to impatient web users), it’s evident that CDNs are must-have utilities. In fact, CDNs form the transparent and undisclosed backbone of the Internet. Whether you know it or not, this web page (and most of the online traffic) is served to you using CDNs.

“A Content Delivery Network (CDN) is a critical component of nearly any modern web application. It used to be that CDN merely improved the delivery of content by replicating commonly requested files (static content) across a globally distributed set of caching servers. … For caching, a CDN will reduce the load on an application origin and improve the experience of the requestor by delivering a local copy of the content from a nearby cache edge,” according to the Amazon AWS.

It brings us to the questions: What is a CDN? Does it really help at speeding up websites? If yes, how does it work? In this post, let’s find the answers.

What is a CDN?

A CDN (short for Content Delivery Network) — is a system of geographically distributed servers (or data centers) that deliver web content to the end-users, according to Imperva. This system of servers works together to quickly deliver web content, including but not limited to HTML pages, CSS or JavaScript files, images and videos, and documents. Its popularity is rapidly growing, thanks to the need for superfast websites after considering the growing sizes of modern websites.

How popular are CDNs? CDNs are almost utilized by every big and small online business on the planet. In fact, this web page is served using a CDN. Then, the searches you make on Google, the videos you watch on Facebook or YouTube, and the shows you binge-watch on Netflix — all are served via CDNs!

Is a CDN equal to a Web Host?

No, CDNs help web hosts perform better, but a CDN can’t replace a web host. It’s not possible for any web app or website requiring computations. Also, if it was possible, it would contradict the primary purpose of CDNs.

Why? It’s the major difference between a CDN and a web host. A web host is just like a Mac or PC, which has its own operating system, a set of programs, and other utilities. The owner or user (if permitted) can install, update, and remove programs per requirements. Let’s say, if the website requires PHP or Python, it can be installed, and the website can create web pages dynamically.

However, a CDN is like a school’s computer, which has its own operating system and programs as well. However, you — as a user — can’t install or remove the programs. You can only use the system as it is; it’s the same with CDNs. A CDN just serves static content, i.e., you can’t perform computations on CDNs. That’s why CDNs are so fast; CDNs don’t process, but just serve content. Of course, it’s not true for modern CDNs — they may serve dynamic content too.

How do CDNs help to Speed up Websites?

In a nutshell, a CDN is just a network of servers spread around the world for delivering content cheaply, quickly, and reliably as possible. CDNs provide a lot many features for speeding up the page-loading times for any website — be it a simple news portal like CNN or a heavy video platform like YouTube.

1. Distribute Content from Nearby Servers

A CDN is “a bunch of servers geographically positioned between the origin server of some web content, and the user requesting it, all with the purpose of delivering the content faster by reducing latency,” according to SitePoint. So, instead of connecting to a website’s origin server, the users connect to a geographically closer server, leading to less travel time, i.e., faster page-loading times.

For example, let’s say your website’s hosting provider has servers in New York, USA. And your user is visiting your website from New Delhi, India. In this case, the content has to travel from New York to New Delhi. However, this situation can be improved by using a CDN, which will reduce the data transit time.

So, let’s assume you opt for a CDN, which has servers all around the world. Then, the data won’t have to travel from New York to New Delhi, but from the nearest location (say, Singapore) to New Delhi. That said, the website will load faster on the user’s web browser since the data has to travel a shorter distance.

Then, CDNs connect to the exchange points of the Internet — the primary locations wherein the service providers connect to each other’s networks for forming the infrastructure of the Internet. Thanks to these direct, high-speed inter-connections with the service providers, CDNs can provide high-speed data delivery, reducing costs and transit times and speeding up websites.

2. Add Hardware and Software Optimizations

CDNs apply a lot of hardware and software optimizations for delivering fast content. These optimizations prove to be super-useful especially if your web server doesn’t apply the necessary optimizations for speeding up the site.

For example, CDNs may use efficient load balancers and solid-state hard drives to speed up content delivery. Moreover, CDNs usually add data minimization schemes such as file compression and minimization. Why? If the content is smaller in size, it’s delivered more quickly, so providing better load times.

3. Improve Content Availability and Reliability

CDNs store duplicate data on their data centers or servers. They just copy the data from a site’s origin servers and distribute them to the site users per the geographical location of the users. In this process, they store duplicate data, which means, your website is available to the users even if its origin server met a problem or shuts down, thus improving a site’s availability and reliability.

For example, if the site’s origin server in New York gets a problem, then the user will get an error when loading your website. With a CDN, the server will get loaded from the server in Singapore, making the website always available.

That’s all about CDNs and how they help at speeding up websites. In doing so, CDNs help at speeding up the Internet. Sounds amazing? Did you find it helpful?