What is a CDN?


What is a CDN?

Whenever you click on a website, you will see that the website loads in minutes and displays its content. What if the webpage’s content takes minutes or even hours to load? You’ll most likely become annoyed and leave the site. Businesses use CDNs on their websites for this purpose. A CDN improves and enhances a webpage’s seamless performance.

Wondering what CDN is? Here is a whole article crafted just for you.

What Does CDN Stand For?

A content delivery network (CDN) is a dispersed group of servers located in different parts of the globe that collaborate together to deliver web content in a matter of seconds.

Ever wondered what phenomena behind the scenes cause the quick and timely delivery of internet content? Well, you guessed it right, it is CDN.

Despite how high the web traffic is, with CDN, webpages can load their vital assets such as HTML and javascript files, photos, and other necessary sections of the website in a short amount of time. 

CDN is utilised and employed by almost every popular website on the internet. Amazon, Netflix, and Instagram to name a few.

Not only does a CDN help deliver optimal performance, but it also safeguards the website from malicious activity such as phishing and DDoS attacks.

How Does a CDN Work?

A Content Delivery Network (CDN) is a cluster of servers that work together to deliver content to visitors quickly, consistently, and secure. 

IXPs make it feasible to achieve such peak performance. IXPs (internet exchange points) are servers placed at the intersections of multiple networks. They ensure that content is delivered to visitors in a reasonable timeframe. 

These Internet exchange points (IXPs) are key hubs where different Internet providers connect to exchange traffic generated by their own networks.

A CDN stores a cached version of your website’s content in many geographical locations to reduce the distance between users and your website’s server, points of presence, or PoPs. Each PoP has a variety of cache servers that take care of delivering content to visitors in the area.

A CDN distributes your material to multiple locations at once, giving your users better coverage. For example, when someone in Germany visits your US-hosted website, they do so through a local Germany PoP. 

Without a CDN 

When a user visits a website without using a CDN, he establishes a connection similar to the one shown in the accompanying diagram. The Local DNS or LDNS converts the website name to an IP address (such as the DNS server provided by the ISP or a public DNS resolution server).

If DNS or LDNS fails to resolve the IP address, the site will attempt to resolve the address through upstream DNS servers. Finally, the request might be routed to the zone’s authoritative DNS server. This DNS server then resolves the address and returns it to the user.

Local DNS to Authoritative DNS

After that, the user’s browser establishes a direct connection with the source and downloads the website content. Each successive request is served directly by the source, and the static assets are cached locally on the user’s PC. If a person from a similar or different location tries to visit the same site, the same sequence will be followed.

Every time a user makes a request, it will be forwarded to the origin, which will respond with content. If the origin is located far away from the user, response times will suffer from significant latency, resulting in a poor user experience.

With a CDN

When LDNS receives DNS requests from users, it routes them to one of the CDN’s DNS servers. These servers are part of the Global Server Load Balancer (or “GSLB”) system. By surveying the entire Internet and keeping track of all accessible resources and their performance, the GSLB improves load balancing functionality.

The GSLB uses this information to resolve DNS requests by selecting the best-performing edge address. The “edge” is a set of servers that caches and delivers online content.

Global Service Load Balancer 

After DNS resolution, the user sends an HTTPS request to the edge. When the edge receives a request, the GSLB servers help the edge servers transmit the request to the origin in the most efficient way possible. The required data is then retrieved, sent to the end-user who initiated the request and stored locally by the edge servers.

All further user queries will be given from the local dataset, eliminating the need to query the origin server. The content kept on the edge can be transferred even if the origin becomes unavailable.

Who Uses a CDN?

CDNs already provide more than 50% of all traffic today. However, in reality, the number of enterprises that use CDN is growing rapidly.

Here are a few examples of businesses that are benefiting from using a CDN:


A content delivery network (CDN) aids e-commerce sites in delivering content fast and efficiently, even during peak traffic periods such as the holidays.

  • Government

Using a CDN, large, content-heavy websites can deliver essential information to citizens much faster and more efficiently.

  • Finance

Banking institutions can use CDNs to quickly, securely, and reliably transmit sensitive data to customers and analysts.

  • Publishing / Media Websites

Publishing / Media Media websites must provide fast and accurate information. A CDN can assist media companies in updating headlines and news homepages as stories develop in real-time and remove data when it becomes obsolete.

  • Apps for Mobile Devices

A content delivery network (CDN) reduces load times and improves responsiveness by delivering dynamic location-based content to mobile apps.

  • Technology and Software-as-a-Service (SaaS)

A content delivery network (CDN) allows technological websites to send web visitors billions of requests per day without sacrificing performance.

Why Use A CDN? 

Still not convinced on whether to use a CDN or not?

Well, then here are some convincing reasons which explain why most businesses are still preferring CDN,

Performance Benefits

Performance is, without a doubt, one of the most compelling reasons to use a CDN. This is a no-brainer if you want your website to load quickly. Here’s a brief test I ran on one of my websites. 

SEO Advantages

The speed of a CDN is one of the most significant SEO benefits, and Google favours fast-loading web pages and considers this in its ranking algorithm. Fast websites also have more time on pages and reduced bounce rates. You can improve your rankings by improving your pace.

Additionally, making your website load faster will boost the number of times Google scans your pages. The faster Google scans your sites; the more likely your material is to be indexed and appear in Google. Then there’s a picture search on Google. You can ensure that Google can access your photos faster by serving them from a CDN.

DDoS Prevention and Improved Security

A CDN can provide additional security. Because the CDN provider serves 60% or more of the traffic, they will mitigate DDoS assaults on their edge servers for you. To manage huge mitigations, 

SSL and Secure Token are two additional advanced CDN security capabilities. You ensure that all traffic between the CDN edge servers and the origin server is encrypted by activating SSL. 

Secure Token allows you to create secure links that expire after a certain amount of time has passed, and people will no longer be able to view the content once it has expired.

Traffic Spikes and Scalability

You never know when a traffic spike will occur when it comes to the internet. Under heavy pressure, most web hosting will become unusable. A CDN can assist you in avoiding this problem. 

The inert material on your website, which often accounts for 80 per cent or more, is cached on edge servers, relieving the origin server of a significant amount of stress. Your origin server doesn’t have to work as hard now that the majority of resources are sent via the content distribution network.

This allows you to make your website far more scalable with little work and avoid any downtime scenarios that could cost you money.


Most of you have definitely experienced your website falling down at some point, which can be inconvenient. It is true that adding more third parties to the mix, such as a CDN, introduces another point of failure. A CDN, on the other hand, delivers reliability due to the way its architecture is set up. 

Requests to your website are always directed to the nearest available POP when using a CDN. If one is unavailable, it simply forwards the request to the next available server. This provides redundancy, resulting in less downtime and a better web experience.

More Affordable

Another prevalent misperception is that CDNs are prohibitively expensive. That is, in fact, the case with several CDN providers. Usually, CDNs are more affordable than hosting providers.

Data Security & CDNs

A CDN’s information security is a critical component. CDNs protect the data on a website in the following ways.

By Providing TLS/SSL Certificates 

CDNs can assist site security by offering Transport Layer Security (TLS)/Secure Sockets Layer (SSL) certificates that ensure a high level of authentication, encryption, and integrity. These certificates guarantee that particular protocols are followed when data is transferred from a user to a website.

Data is subject to interception by hostile actors when sent over the internet. This is solved by encrypting the data with a protocol that allows only the intended recipient to decode and read it. TLS and SSL are examples of encryption technologies that encrypt data transferred over the Internet. 

Secure Sockets Layer (SSL) is a more advanced version of SSL (SSL). If a website begins with HTTPS:// rather than HTTP://, it uses TLS/SSL certification, indicating that it is secure enough for communication between a browser and a server.

Mitigating DDoS Attacks

The CDN functions as a security service against attacks on your website and web application since it is put at the network’s edge. A CDN is also perfect for preventing DDoS floods due to its dispersed infrastructure and on-edge location. 

Because these floods must be dealt with outside of your prominent network architecture, the CDN will distribute them to multiple points of presence (PoPs) based on their origin, avoiding server saturation.

Blocking Bots and Crawlers

CDNs can also restrict threats and limit the use of your bandwidth and server resources by abusive bots and crawlers. This reduces your bandwidth expenses while also limiting additional spam and hacker threats.

What Are the Benefits of Using a CDN?

The benefits of using a CDN include:

Improving Website Load Times

Visitors see faster page loading times by using a nearby CDN server to distribute material closer to website users (among other optimisations). 

Visitors will usually avoid sites that take too long to load. Such an issue is not a concern with CDN because the sites will run quickly and smoothly, attracting more visitors.

Reducing Bandwidth Costs 

For website hosting, bandwidth consumption charges are a significant price. CDNs can reduce the quantity of data an origin server needs to offer through caching and other improvements, lowering hosting costs for website owners.

Increasing Content Availability and Redundancy

The usual operation of a website can sometimes be affected due to high traffic or hardware issues. Multiple origin servers can’t handle as much traffic and can’t withstand hardware failure as well as a CDN.

Improving Website Security

A CDN enhances the website’s security by providing DDoS mitigation, security certificate upgrades, and other vital enhancements.


For a webpage to function correctly, it must be equipped with tools that can make it load faster and seamlessly. This feature is taken care of by CDN.

We hope you were able to understand what CDN is and how employing CDN will enhance your website’s performance and security.

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