Acronym Monday: CDN

What does CDN mean in plain English?

In our technological world, there are hundreds of technology-related acronyms that programmers and developers have been able to define since they were in their coding diapers. Sometimes it doesn’t come as easy for everyone else. Wildcard deals with tons of non-technical clients, and we have perhaps just as many non-technical team members. In honor of these people, we have decided to take one day out of every week to explain some of these acronyms. We are calling this day “Acronym Monday” in an arguably fruitless effort to make Mondays exciting and something to look forward to.


Today’s Acronym Monday is brought to you by the acronym CDN.

CDN stands for content delivery network. All those words strung together may not mean much to you at first, but let’s unpack the term a little. We already talked about what “content” is in last week’s Acronym Monday post about content management systems, and remember that, in the most basic of terms, content is anything visible on a website. But what does “delivery” and “network” mean in this context?

Delivery

A content delivery network isn’t some kind of newfangled parcel service. Delivery in this sense means to send through the web. When you access a website for instance, the content you see hasn’t just been sitting inside your computer or smartphone waiting for you to click on it. It has to be delivered to you from somewhere else. Often that "somewhere else" is a single server that the website is hosted on.

Websites live on servers. A server is a computer that provides access to data. So you access a website, and the server sends the website content to you. But when a website becomes popular enough, or is accessed from all over the world, that single server is usually not enough to send the website to everyone quickly. Those websites need a “network” of servers to help.

Network

In the context of a CDN, Network means a series of connected servers in different locations. Let’s pretend your website is accessed by people in countries all around the world. The servers on your CDN should ideally be located all around the world too, so that there is always one nearby to one of your visitors.

Now, all the servers that form a content delivery network do not host the entire website. They host snapshots of the website in a cache. For example, the content delivery network saves pieces of a website—like a page or even a content item—and then serves out those pieces to visitors that are nearby, thus speeding up the load time of the website for that visitor.

Think of it this way: you have a typewriter. You type up an exciting, one-page document for a business meeting, and it took about five or ten minutes. You need ten copies for your ten colleagues who will be at the meeting. They all need to see it at the same time, so you can’t just pass it around to them. You would have to type the document up nine more times in order for them to all be able to read it at once. But the meeting is in 3 minutes, and they don't want to wait for you. They will lose interest, no matter what's on your piece of paper, and you will miss an amazing opportunity to prove your worth. Fortunately you have just purchased a brand new photocopier. You run the document through the photocopier and save yourself lots of time and lots of work by taking snapshots of your document. Now each of your colleagues can see the document at the same time, thus navigating a lot of potential problems.

In the above analogy, the typewriter is the server that hosts your website, the document is the actual website that people see, and the photocopier is the content delivery network.

When to use a CDN

A CDN usually works best at times of high traffic, which could be hundreds or thousands of legitimate visitors—just like yourself—visiting the website at the same time. But it could also be a cyber attack based on thousands or even hundreds of thousands of fake users—most likely not like yourself—at the same time, meant to slow a website down to a stop. The CDN can take a huge load off the main servers, maintaining the illusion that the website is running smoothly, even though it may be totally bogged down by traffic.

The content delivery network is also used for static content, which is content that doesn’t change very often. Since there isn’t typically anything new on a static page, a nearby server on a CDN can safely serve out a cached copy of the page instead of the actual live page, and it can do it much faster. Very few people will even notice the difference.

We already mentioned how a CDN can help if you have a worldwide audience, but I’ll explain a little more. Let’s say you live in Muravlenko, Russia and you’re trying to browse a website that is hosted on a server in Stevens Point, Wisconsin about 4,900 miles (7,885 km) away. It takes much longer for that server to send the website to you than it would to someone in Stevens Point, just two blocks away from the server. But if the website was using a CDN, and one of the servers on the network was located in the data center in Kirov, Russia, at 895 miles (1440 km) away, the website’s cached content could be sent to the visitor much faster.

Security

Another reason to use a CDN is if your website is in above average danger of a cyberattack. Government websites are attacked in some way, shape, or form several thousand or even several million times a day. If an attack is successful and the website is brought down, a CDN can minimize the impact to the public by sending out cached content, giving the administrators of the website time to deal with the attack before anyone in the public even knows something went wrong. A CDN can be an invaluable tool to government organizations of any size.

Major CDN Providers

We provide content delivery networks to many of our customers. Some of the vendors that we have used and would recommend to others are:

  • Cloudflare—One of the most agile and advanced vendors
  • Level 3—One of the largest networks
  • Akamai—A more expensive, yet valuable option

Your web developer should be able to tell you whether you need a CDN or not, and they should know which vendor is right for you. If you are looking for a custom website or would like to know if you should be using a CDN, contact us today at 715-869-3440 or via email at info@wildcardcorp.com. Or you can use our “contact us” form on our website at www.wildcardcorp.com.

Next Monday we will be unpacking the acronym DDoS, and you won't want to miss that.