What Is a CDN and How Does It Work? (With Benefits)

By Indeed Editorial Team

Published May 2, 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.

Web-based companies and experts typically rely on high-speed internet connectivity and brief load times to fulfill their professional and operational targets. CDNs are an example of a service they often use to help accomplish this. Understanding how a CDN works can assist you in determining the next stages of projects and developing your knowledge of the internet. In this article, we define "What is a CDN?", differentiate it from a web host and the cloud, explain how it works, discuss how it can safeguard data, describe how it can improve and maintain websites, and share some benefits of using it.

What is a CDN?

To answer the question, “What is a CDN?” involves knowing that it stands for content delivery network. A CDN is a collection of geographically distributed servers that can accelerate web-based information delivery by being physically close to end consumers. These servers are usually data centers and they aid in the management of temporary file storage, referred to as caching, which can enable you to access online material on web-enabled devices such as PCs, smartphones, and tablets. CDNs can hold different types of content, including the following:

  • Internet pages

  • Style sheets

  • Videos

  • Pictures

  • HTML documents

  • JavaScript files

CDNs are a response to the increased use of rich web content, such as graphics and video across the internet, which resulted in network congestion because of the size of files in use and a network's available capacity. By temporarily storing this content on CDNs you can perform specific tasks online, such as:

  • Purchasing items

  • Making social media posts

  • Verifying your bank account

  • Downloading software

  • Seeing a film

Related: How to Become a Network Engineer (With Job Roles and Salary)

What distinguishes a CDN from a web host?

A CDN varies from a web host because it doesn't actually host data. In the context of the internet, a web host is a service that uses servers to develop and manage websites for its clients. These servers can be in any location and several of the bigger web hosting companies maintain servers in multiple countries. While a CDN can improve website performance to a certain level, it often does this by leveraging the network of computers and the internet. The CDN doesn't fully host an entire website, but rather certain sections of it, such as videos, photos, and downloads.

What distinguishes a CDN from the cloud?

A CDN also varies from the cloud. The distinction is that the cloud's primary goal is to store data for future use, while the principal objective of CDNs is to disseminate information with minimal delay. Another distinction between the cloud and a CDN is that CDNs are usually in considerably more locations to ensure physical servers remain close to their end consumers. In contrast, cloud servers often have fewer, more centralized servers that can store higher volumes of information.

Businesses also engage both server types differently. For software and technology firms, developing websites and services that are CDN-compatible can be significantly easier, as most technologies and software often have designs that incorporate the content that CDNs temporarily store. Cloud services and software can be significantly more challenging to develop since the cloud is a dynamic resource that changes frequently.

How does a CDN function?

CDNs work by lowering latency, or the time delay encountered by end customers while working with web-based services. Latency is the time interval between an instruction for the transfer of data and the start of the actual transfer. While latency typically lasts for only a few milliseconds, it may occasionally be long enough to create page load issues or server time-out. Generally, CDNs minimize latency by having a physical location close to the end-user. For instance, if someone uses a computer in a particular town to broadcast a video, there's usually a CDN located reasonably close to that area that reduces the amount of work required of the user's computer.

Who uses CDNs?

Almost everyone who uses the internet does so with a CDN, whether or not they are conscious of it. The following are some examples of people who may use CDNs on purpose:

  • Content owners, such as online e-commerce platforms, cloud service enterprises, and media companies

  • Network service providers, such as third-party content companies and mobile carriers

Both sets of people usually leverage CDNs to minimize the amount of work required to provide their respective services, enabling their applications and websites to run more efficiently and with less interruption. As a result, businesses may also see an increase in consumer satisfaction for creating a more seamless service.

How does a CDN safeguard data?

Information security is an essential aspect of a CDN. A CDN can maintain a site's security by renewing TLS or SSL certificates, which can ensure a high level of encryption, authentication, and integrity. Transport layer security (TLS) is a coded protocol developed to offer secure and safe communications over a network. It replaced the secure sockets layer (SSL) protocol.

This replacement occurred primarily to avoid legal complications with the corporation that invented SSL and to allow the protocol to remain free and open standard. A CDN can examine the security breaches around data centers and determine what to do to ensure the secure delivery of information.

Read more: 10 Top Security Certifications for IT Professionals

How can a CDN enhance website load times?

When it concerns websites loading information, visitors typically leave when a site becomes slow. CDN services can help with load time minimization in these ways:

  • Proximity: A CDN's global distribution makes it possible to lessen the physical distance between site visitors and the resources on a website. Rather than connecting to the origin server of a website, a CDN can allow people to link to a physically closer data center, which can reduce connection travel time and create better service.

  • Optimizations in software and hardware: CDNs enable optimizations, such as effective load distribution, because these features can help information get to the client more quickly.

  • File compressing: CDNs can lower the volume of data transmitted by compressing files. Reduced file sizes can help create faster loading times.

How does a CDN maintain website uptime?

For any person who owns an online site, uptime is crucial. Hardware malfunctions and traffic surges, whether triggered by malicious cyberattacks or just increased popularity, can cause web server downtime and prevent clients from using a website or service. An effective CDN usually possesses the following attributes to help decrease downtime:

  • Load balancing: A CDN uniformly spreads network traffic across multiple servers through load balancing. This feature makes it easier to manage increased site traffic.

  • Intelligent failover: Intelligent failover ensures that service remains available even if one or more CDN servers go down due to equipment failure. The failover can redirect traffic to the remaining functioning servers.

  • Anycast routing: Anycast is a network addressing and routing methodology in which devices, generally servers, share a single destination IP address in multiple locations. If a whole data center experiences technical difficulties, Anycast routing can help shift traffic to an operational data center so users can reach the website.

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What are the benefits of using a CDN?

Some benefits of employing CDNs include the following:

Reducing site load times

CDNs often aid in the reduction of page load times. The load time is the amount of time a website requires to load from when a user clicks on a link or types in a URL to when the page displays on their device.

Generally, faster load times result in increased user satisfaction and enhance the length of time an average user stays on a site. This positive change in user behaviour can be helpful for commercial businesses as it allows them to expand the number of items displayed on their webpage. As a result, the business may experience an increase in expected sales because consumers can view more items that may interest them within a shorter period.

Reducing bandwidth expenses

Bandwidth refers to the amount of space occupied by a site, image, video, or another type of media on a network. CDNs can decrease data volume requirements for an origin server through caching and other technologies, lowering hosting expenses for site owners. CDNs can also help manage the general bandwidth of numerous networks concurrently because they allow each one to handle more data, improving the speed at which they deliver information.

Increasing content availability and redundancy

Several websites and applications typically depend on CDNs' decentralized structure. Too much traffic can hinder a website's ability to deliver its services accurately and quickly. Because CDNs are in several locations globally, the traffic volume necessary for a single website to process becomes minimized, enhancing the website's general availability.

Additionally, CDNs can improve the content's redundancy. Redundancy is the process of duplicating essential parts or processes of a system to improve the system's dependability, typically in the format of a fail-safe or backup storage. This feature can enable organizations to quickly recover from hardware problems by temporarily storing their data in a CDN. As a result, websites usually experience reduced downtime and interruptions for most users.

Read more: How to Become a Cloud Architect in 4 Steps (With Skills)

Enhancing the website's security

Because hackers occasionally target sites and other web-based applications, increasing security is one approach firms may use to improve their systems. CDNs usually provide some level of protection on their own systems, which increases the capability of a server to rebuff an attack intended to take it down. CDNs can also help institutions design websites and software adapted for security with better security certificates.

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