What Is A CDN And Why Is It Important? (With Applications)

By Indeed Editorial Team

Published 19 July 2022

The Indeed Editorial Team comprises a diverse and talented team of writers, researchers and subject matter experts equipped with Indeed's data and insights to deliver useful tips to help guide your career journey.

With the growth in media and web pages, it is imperative to improve the performance of websites, visitor experience and conversion rates. A content delivery network (CDN) helps provide content available in a variety of formats, such as text, images, documents, software and on-demand streaming media to users and networks all over the world. Understanding how CDNs work can help you improve your website's performance and the overall user experience. In this article, we answer the question, "What is a CDN?", learn how it works and find out some applications and benefits of CDN.

What Is A CDN?

Learning the answer to "What is a CDN?" can help you deliver content quickly and seamlessly to your audience across the globe. A content delivery network (CDN) is a system of servers that can handle large traffic loads in different locations and reduce the time it takes for content to be delivered to the end-user from servers. A user's physical distance from a website server affects the duration it takes for the content to appear on their screen.

Globally distributed data centres reduce bandwidth consumption and increase content delivery speed regardless of the user's location in relation to the main server. The CDN duplicates content from other servers and directs it from the closest data centre to the user. Here are some terms associated with CDNs:

  • Origin server: A website's origin server is the primary source of its data and where it hosts its files.

  • Network edge: It is an area where local networks or devices interface with the Internet.

  • Edge server: An edge server is a server located at the network edge that caches content retrieved from an origin server.

  • Point of presence: Point of presence (POP) refers to the physical locations of edge servers.

Related: What Is A Data Centre And How Does It Work? (With Types)

How does a CDN work?

To illustrate the working of a CDN, consider an example where a client wants to stream a movie. The client, living in Amritsar, requests data from the website movies.co whose server is located in New York. Here are the steps in which a CDN works:

Client requests data from a server

The client requests data from a server located in New York. The web browser of the client requests the data by sending data packets to a web server. In response to the request, the web server requires sending the data packets back, which contain the data. Each of these cases requires the data packet to travel across the Internet through bridges, routers and gateways and from different networks to reach its destination.

The connection is fast if the server and client are close to each other and vice versa. There may be a requirement for a CDN when the server and user are located far apart. The website requires a CDN to optimise performance due to the distance between Amritsar and New York.

Related: What Is A Web Application? Definition and How It Works

The CDN connects to the server

A CDN connects the client to the optimal server, which focuses on saving time by minimising the distance between the website's server and the end user's browser. A client's optimal server is usually the one that's closest to their current location, also known as an edge server. The CDN would cache the New York website in different geographic locations around the world, called points of reference (PoPs). Servers serve as content delivery tools, reducing latency, which is the time it takes for a web page to load completely.

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The CDN caches the data

The content delivery network server caches static content at different PoPs that store the media files for any similar user requests from that same geographic area. There are nodes and caching servers within each PoP that distribute the content to the end-users according to their geographical location, so they can receive it with accelerated speed.

Related: 7 DNS Interview Questions (With Explanations And Answers)

Applications Of CDN

Several real-time application areas highlight the benefits of CDNs. Here are a few examples of common applications:

  • E-Commerce: E-commerce companies use CDNs to improve their site performance and make products available online. This improves global website performance and maximises business outcomes by ensuring complete uptime of e-commerce sites.

  • Media and advertising: By delivering high-quality content efficiently, media, advertising and digital content providers leverage the growth of streaming content. A CDN provides fast access to streaming media content, such as movies, audio, news and multimedia games in a variety of formats.

  • Education: Educational institutions offer many online courses with video/audio lectures, presentations and images. Whenever a student logs into a course, the CDN delivers the content from the closest data centre to them. Using CDNs, educational institutes can route content to regions where students are most likely to reside.

  • Business websites: CDNs facilitate user-website interaction with high speed, which is an important ranking factor and metric for corporate businesses. CDNs deliver requested content to users from the nearest server, thus speeding up the delivery process and overcoming the slow loading of pages problem.

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Benefits Of CDN

Here are some benefits of CDN:

Fast performance and lower latency

Content delivery networks allow users to connect to a data centre closer to them instead of the origin server of a website. The CDN servers distribute website content closer to website users, making it faster for them to load pages. The elimination of slow-loading site pages through CDN servers can reduce bounce rates and latency. This reduces the distance travelled and web pages load faster, so the original server is under less load.

Related: Bounce Rate Vs. Exit Rate: Differences, Examples And FAQs

Better availability

Availability means that end-users can always have access to the content during peak traffic periods when many people are searching for the same content. The spike in Internet traffic raises the demand for powerful servers that would handle all the traffic without a content delivery network. This can easily lead to crashes or a poor end-user experience. CDNs address these types of issues because of their wide accessibility. Using advanced CDNs, content providers can serve larger audiences with their improved architectures and large server platforms to handle more traffic.

Related: 10 Load Balancing Interview Questions (With Sample Answers)

Improved security

Using content delivery networks allows websites to handle higher traffic volumes and prevent distributed denial-of-service (DDoS) attacks, man-in-the-middle attacks, firewall issues and other threats with the help of analytics and automation tools. CDNs provide security by installing firewalls between malicious users and websites. A CDN can also provide new Transport Layer Security (TLS) certificates for improved authentication, integrity and encryption. They also enhance content availability and redundancy, maintaining service during periods of server downtime.

Related: What Is A Firewall? (With Benefits, Types And FAQ)

Cost-efficient

CDNs deliver a cost-benefit to companies by lowering bandwidth costs. They provide strategic access to PoPs located near major peering points on the Internet that optimise bandwidth efficiency and improve the delivery of media content, which results in noticeable website performance. Using CDNs also eliminates the need for expensive servers and advanced infrastructure.

Improved audience reach

A CDN makes it easier and inexpensive to deliver content to users based far from a company's headquarters and its main servers. This helps customers experience a consistent user experience. It also allows businesses to scale effectively into new markets and expand their audience by ensuring customer satisfaction.

Related: What Is Prospecting? (Methods And Steps To Reach Prospects)

Tips For Choosing The Right CDN

While CDNs are similar, they differ in several ways. Here are some factors you can consider while choosing a suitable CDN for your website:

Price

CDNs typically charge based on bandwidth usage. Some companies charge based on the refreshes, the number of cache hits and cache misses. Some offer a fixed fee and a certain amount of bandwidth over time. It is important to consider your bandwidth needs and expected growth when comparing different content delivery networks.

PoP locations

Some PoPs can serve your users more effectively based on where they are located. Choosing a CDN that manages PoPs near your users is the best way to maximise CDN performance. This also boosts your website performance and user experience.

Related: What Is A Data Centre And How Does It Work? (With Types)

Availability and reliability

While CDNs strive for perfect uptime, there is no guarantee of it. Consider the availability needs of your website and the capabilities of each CDN. You can also compare CDNs based on their PoP uptime instead of their overall uptime, especially in regions you serve.

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