Q&A: What is a CDN? (Definition and Benefits)

By Indeed Editorial Team

Published December 14, 2021

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.

Web-based businesses and professionals all around the world rely on high-speed internet access and short load times to accomplish their professional and organizational goals. One type of service they rely on are CDNs. Knowing what a CDN is, and how they work can help you decide the next steps for projects and understand the internet more completely. In this article, we host a question-and-answer session about CDNs, including what they are, their benefits and who uses them.

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What is a CDN?

Content delivery networks, or CDNs for short, are an array of geographically distributed servers that speed up the delivery of web-based content by being close to where end-users are. These servers are data centers and they help control the temporary storage of files, known as caching, so you can access internet content on web-based devices such as computers, smartphones and tablets. CDNs can store a wide variety of content, including:

  • Web pages

  • Videos

  • JavaScript files

  • Images

  • HTML files

  • Style sheets

Storing this material temporarily on CDNs allows you to do certain things online, such as:

  • Downloading software

  • Watching a movie

  • Making purchases

  • Checking your bank account

  • Posting on social media

CDNs are a response to the increase of rich web content such as graphics and video over the internet, which caused network congestion because of the size of files people were using and the relative capacity a network could provide.

How does a CDN work?

CDNs work by reducing latency, or the delay end-users experience when using web-based services. Latency is usually only a few milliseconds long, but this is sometimes long enough to cause load errors on webpages or for servers to time-out. Typically, CDNs reduce latency by having a geographic lobation near where the end-user is located. For example, if someone is using a computer within a particular city to stream a video, there is often a CDN somewhere relatively nearby that city, reducing the amount of work the end-user's computer has to do. This decreases latency because the information is nearby.

Is a CDN different from a web host?

A CDN differs from a web host because it doesn't actually host data. In terms of the internet, a web host is a service that creates and maintains websites for its clients by using servers. These servers can be located anywhere in the world and many of the larger web hosting services have servers in several countries. While a CDN increases the performance of websites to some extent, it does so by working within the network of computers and the internet and never truly hosts an entire website, only parts of it such as videos, images and downloads.

Related: What Is a Network Consultant?

Is CDN different from the cloud?

A CDN also differs from the cloud. The difference is that the primary function of the cloud is to store data for later use, while the primary function of CDNs is to distribute information in a way that reduces latency. Another difference between the cloud and a CDN is that CDNs are in a lot more locations, in order to have physical servers close to their end-users, while cloud servers have fewer, more centralized servers which can store a lot more information.

Business' interact with both types of servers differently as well. For software and tech industry companies, creating websites and services that are compatible with CDNs is much simpler because they design most technologies and software to include the information that CDNs temporarily store and CDNs change little. Cloud applications and software are much harder to accomplish because the cloud is a dynamic service and changes often.

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Who uses CDNs?

Almost every person who accesses the internet is using a CDN, regardless of whether they are aware of it. Some people who intentionally use CDNs include:

  • Content owners, such as e-commerce websites, cloud computing companies and media properties.

  • Network service providers, such as third-party content owners and network operators.

Both groups of people use CDNs to offload the amount of work that their particular services have to provide, allowing their applications and websites to work faster and with little interference. this can help generate higher customer satisfaction.

What are the benefits of using a CDN?

Below are several benefits of using CDNs:

1. Decreasing website load times

CDNs help to decrease the load times of websites. Load times are how long it takes for a website to load from the time a user clicks on the link or enters a URL to when the page appears on their screen. Typically, faster load times lead to more satisfaction among users of the website and increase the time an average user spends on a website. This can be helpful to commercial businesses because they can increase the number of items a user sees on their website and potentially earn higher profits by making more sales.

2. Reducing the costs of bandwidth

Bandwidth is the amount of space a particular website, graphic, video or other media takes up within a network. For organizations that have web-based services such as an online market or a video streaming platform, reducing the amount of bandwidth they use can increase their profits because they can afford smaller networks. CDNs can help these organizations by reducing the amount of space each one needs in order to operate. CDNs can also help the overall bandwidth of several networks simultaneously because they allow each one to process more information, increasing the speed at which they deliver information.

3. Improving the availability and redundancy of content

Many websites and software rely on the decentralized nature of CDNs. Too much traffic can decrease the ability of a website to perform all of its functions quickly and accurately, but because CDNs are located all over the world, the amount of traffic a single website has to work through becomes limited, increasing the overall availability of the website. CDNs also increase the redundancy of content. This can help organizations quickly recover from hardware failures by keeping their data within a CDN briefly. This means that websites have less downtime and interruptions to most people using that service.

Read more: Network Redundancy: Definition, Types and How To Implement

4. Increasing the security of websites

Hackers and sometimes target websites other web-based services, so creating more security is one way that organizations try to improve their programs. CDNs provide a certain amount of security with their own systems, leading to DDoS mitigation or the ability of a server to nullify an attack meant to shut it down. CDNs can also help organizations design websites and applications that are optimized for security and come with improved security certificates.

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