What is a CDN? Understanding Content Delivery Networks

What are CDNs and How Do They Work?

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A CDN is a way to deliver content to web users using multiple servers and data centers. These servers cache your content temporarily, storing copies of files to make them more accessible to nearby users.

CDNs are one of the most common tools leveraged by website owners, content creators, community managers, and business leaders across the globe.

A Content Delivery Network, or “CDN” is a geographically distributed collection of servers, working in tandem to accelerate internet connections, and improve the delivery of web content. Used correctly, it can speed up site performance, improve security and more.

Here’s everything you need to know about Content Delivery Networks.

What is a CDN? An Introduction

A CDN allows you to divide the task of delivering content to web users across a multitude of different servers and data centers. Across the globe, different data servers “cache” your content, temporarily storing copies of files so they can be accessed closer to the use.

CDNs can cache content like web pages, videos, and images, in servers known as “proxy” servers, close to a user’s location. The closer the cache is to the physical location, the faster the user can access the content they want, without having to deal with longer loading times.

CDNs can be configured in a multitude of different ways. However, their primary purpose is to make content more accessible, and improve loading times. They were designed to solve the common problem of network congestion, created when business leaders began producing richer web content, such as video and graphics. Properly configured CDNs can also help to protect websites against common security concerns, such as “distributed denial of service” or DDoS attacks.

CDN vs Web Host: What’s the Difference?

One of the reasons people tend to get confused about CDNs, is they’re very similar to web hosts. Both tools allow you to deliver content from the web to your user. However, there are some major differences. CDNs don’t actually “host” the content you produce and share online.

As such, CDNs can’t replace the need for proper web hosting. You still need to host your content with a provider so it can be accessible online. CDNs simply help to cache the content at the network edge, to improve performance. As a result, many companies offering hosting services also provide CDN functionality at the same time, combining the two solutions tin one.

Think of it this way. If the hosting provider for your website was your bank, the CDN would be the network of ATMs you use to gain instant access to your money (content). CDNs help to address some of the common issues of traditional hosting, preventing interruptions in service and improving overall security and performance.

The Difference Between Cloud Tech and CDNs

The evolving world of digital experiences has led to changes in how many companies deploy and share content. CDNs and cloud computing were both developed to address the evolving demand for web content and applications, boosting speed and scalability. However, there are some differences.

Cloud computing environments store data on online servers, rather than on a hard drive. This can be a convenient way to access file storage, email, file sharing, and backup capabilities. Cloud environments consist of various points of presence, or PoPs, with centralized regional locations.

Cloud solutions offer low upfront costs and fantastic scalability. However, many companies can sometimes encounter unexpected costs when building applications and migrating content into the cloud, the dynamic nature of migration projects can make it harder to maintain availability.

CDNs work as a network of servers designed to distribute content from an origin server, using caching to maintain content closer to each end user. Caching content in a location physically closer to the end-user reduces the geographical distance the content needs to travel. Some people refer to these networks as “the edge”, where digital and physical worlds meet.

With Points of Presence distributed around the globe, CDNs can provide fantastic proximity to end users, allowing individuals to access the same content faster, wherever they are in the world.

How Does a CDN Work?

A Content Delivery Network might seem like a complex concept at first, but it’s actually relatively simple. A CDN is essentially just a network of servers linked together around the world, to provide you with an opportunity to deliver content as quickly, reliably, and securely as possible.

The core purpose of a CDN is to reduce latency – the delay users experience when trying to access a video or web page before it has time to fully load onto a device. Though latency generally only delays content delivery by a few milliseconds, it can significantly disrupt user experience. Content Delivery Networks alleviate the latency by reducing the distance content needs to travel to reach users.

To improve speed and connectivity, CDN solutions place servers at the “exchange points” located between different networks. These IXPs (Internet Exchange Points) are the locations where different internet providers can connect to provide access to traffic. Connecting to these aligned locations allows CDN providers to reduce transit times significantly.

Aside from placing servers in IXPs, CDNs also optimize various client/server transfers. CDNs can place data centers in strategic locations around the world, enhancing security, and reducing the risk of internet congestion and delivery failures. While these tools are primarily used for the delivery of web content, they can also support HD-quality video, audio streams, software downloads, updates and more.

The Benefits of Using a CDN

CDNs have been around for quite some time, and are utilized all over the world by companies attempting to reach their customers in different parts of the globe. CDNs balance traffic to ensure everyone accessing online content can enjoy the best experience possible.

The exact benefits of a CDN can vary, depending on the service provider and how the solution is configured, but some of the most common benefits include:

1. Improving web performance

Perhaps the most significant benefit of a CDN is the ability to improve website performance by reducing the need for content to take a round-trip from an origin server. The globally distributed network can reduce the distance between users and website resources, ensuring users can access content from the server closest to them. Hardware and software optimizations can be implemented, such as efficient load balancing, or solid state drives, to boost performance further.

CDNs can also reduce the amount of data transferred, using file compression and minification to reduce loading times. Additionally, CDNs can optimize connection reuse for companies using TLS/SSL certifications to protect their website.

When requested content is cached by a CDN’s server, the mobile or internet service provider accesses the content by connecting to a server in the network, rather than waiting for a request to go all the way to the origins of the site. If the content isn’t saved already, the CDN can use built-in programs to overcome delivery channels, and deliver more dynamic experiences.

By distributing content faster, CDNs reduce issues like high bounce rates and poor user experience, which can further enhance the reputation of the site.

2. Increasing availability and reliability

Achieving a high level of “availability” on a website means ensuring website content is accessible to end users, even during periods of peak demand. When traffic loads increase to millions of requests per second, sometimes even the most powerful servers can struggle. Without a CDN, the traffic needs to be managed by the hosting provider’s infrastructure, which can lead to failures.

A well-rounded CDN helps to alleviate these features, by distributing traffic to a range of different locations. Load balancing technology is used to help evenly deliver traffic across different servers, making it easier to scale to rapid changes in traffic. Additionally, intelligent failover solutions provide uninterrupted service, even if one or more servers go offline.

In an instance wherein an entire data center might be struggling from technical issues, a CDN can transfer the traffic to another available data center too. This improves redundancy, and ensures no users are unable to access the site.

3. Boosting website security

Another major benefit of a CDN is its ability to improve information security. As the number of users on the internet continues to grow, so too does the quantity of attackers attempting to exploit them. DDoS attacks and similar problems can be extremely costly for business leaders.

SQL injection, web-based exploits like cross-site scripting and more can often be launched alongside DDoS attacks, making it difficult to distinguish between good and bad traffic. In these attacks, a CDN solution makes it easier to track the changes in traffic, and protect content.

CDN sites can be secured with fresh TLS/SSL certification, to improve encryption, authentication, and integrity. Additionally, many CDN providers also offer additional security measures to help companies mitigate different attacks.

4. Reducing costs

In some cases, CDNs can even help business leaders to reduce the costs associated with managing bandwidth. Whenever an origin server responds to a request for content, a certain amount of bandwidth is consumed. With a CDN, the number of origin requests is reduced.

Using caching and other strategies, CDNs can significantly lower hosting costs for website owners, allowing them to deliver phenomenal experiences, without huge expenses. Additionally, CDN providers can also collect huge amounts of data about device types, end-user connectivity, and browser experiences worldwide, which can help companies make intelligent decisions.

Customers can use real-time monitoring and analytics to ensures they’re delivering content effectively, improving profitability and ROI.

Who Uses CDN Technology?

Virtually anyone with access to the internet can benefit from using a CDN. These tools were created to deliver faster, more reliable online experiences to every potential user. They’re used not just by content and application owners, but also by network service providers and end-users.

The core people who leverage CDNs today include:

  • End users: Websites and content delivered through a CDN deliver faster loading, transaction, and other experiences to end-users. While many people leverage CDNs on a daily basis, not everyone knows they’re actually interacting with these tools, as they operate seamlessly on the back-end, without disturbing user experience.
  • Content owners: Application and content owners leverage CDNs to help improve customer experiences, increase ad impressions, reduce abandonment rates, and boost conversions. These tools can even help to strengthen customer loyalty and improve web security.
  • Service providers: As online streaming and other rich media services become more component, service providers are becoming increasingly reliant on CDNs. Many network operators launch their own content delivery networks to reduce subscriber churn and lower traffic on the core network. These CDN experiences can also be resold to other customers.

Today, countless companies use CDN technology to deliver internet content to web traffic from around the globe. CDNs are relatively easy to use without the need for tutorial and guide support. They can also come with additional tools like web application firewall (WAF) capabilities, which can improve security for social media apps, videos, and more.

Do You Need a CDN?

CDN services can be an excellent tool for any company looking to deliver faster routing for web application content, APIs, and e-Commerce pages. These edge servers minimize the time associated with page load on common traditional hosting platforms. They help to reduce DNS security attacks, and ensure users in any geographic location can access the best possible experiences.

Thanks to their benefits, such as reduced bandwidth consumption and dynamic content distribution, CDNs can rapidly process user requests, and deliver both dynamic and static content in a shorter space of time. They can be used to deliver HTML, CSS and JavaScript information, as well as videos, and apps. Even major companies like Amazon use their own CDN solutions.

The pricing and functionality of each CDN can vary, depending on what kind of web server you’re using. Companies like Cloudflare and Akamai are relatively well-known for delivering exceptional caching services around the world, alongside automation tools for web server management, video streaming, and DDoS protection. However, as the demand for reduced bandwidth costs continues to grow, the number of CDN providers is growing.

If you’re planning on delivering multiple types of content to multiple forms of network traffic from around the globe, leveraging caching servers from a CDN can help you to minimize downtime, manage traffic spikes, and improve the experience of your users.

Rebekah Carter

Rebekah Carter is an experienced content creator, news reporter, and blogger specializing in marketing, business development, and technology. Her expertise covers everything from artificial intelligence to email marketing software and extended reality devices. When she’s not writing, Rebekah spends most of her time reading, exploring the great outdoors, and gaming.

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