Welcome to a topic that will kick off our new web hosting series. We’ve talked about specific web hosts in the past, but with this new series we’re going to work through all of the hosting questions readers like you have asked us.
Today we’re going to talk about an important technology that everyone on the Internet should know.
There’s almost a 100% probability that you’ve enjoyed the services of a CDN before – without knowing it – unless of course you haven’t used Google, or Twitter or Facebook.
If you’re a blogger, copywriter, webmaster or a WordPress enthusiast, this topic is going to help you understand one of the most important technologies that fuel the Internet.
How will a CDN help my website?
In short –
A fast website means a better user experience which in turn means more sales.
- A survey conducted by Akamai and Gomez.com shows that half of the Internet users expect a site to load in 2 seconds or less, and they tend to abandon a site that isn’t loaded in 3 seconds.
- 79% of web shoppers who face any difficulty in a site’s shopping experience say that they won’t return to the site to buy again. And half of them will tell their friends about the unpleasant shopping experience. That’s bad press for your business.
- TagMan’s 2012 study show that a second-long delay causes a 7% drop in conversions, an 11% drop in page views and a 16% drop in customer satisfaction.
- And then there’s Google, which delivers millions of search results for a single query in about one-fourth of a second. Naturally, Google will want to keep only those websites at the top of their SERP (search engine results page) which are informative, authoritative and fast. Avoid that last factor, and you’ll lose out on potential SEO scores.
With this newfound knowledge, we can fairly assume that a fast website is necessary for a business to succeed. Enter a CDN.
A CDN loads your website faster, which delivers a better user experience and ultimately helps grow your business.
So what exactly is a CDN?
For starters, it’s a technology. A CDN, i.e. a Content Delivery Network is a network of servers strategically located in different parts of the world. Each server holds a copy of a website’s content (files, images, scripts, etc.) and serves it to the site visitors within its locale.
This is one of the most condensed definitions I could come up with. Let me explain the highlighted terms one by one.
Okay, so we’ve established it’s a technology. Just like high-speed fiber-optic cables, this technology (CDN) is used to deliver content faster across the globe, throughout the Internet. So the job of a CDN is efficient, high speed, low-latency content delivery.
A CDN is made up of a network of servers. That means thousands of (insanely powerful) servers housed in datacenters with high bandwidth throughout.
These datacentres are strategically distributed across the globe to achieve minimum distance from the “Internet-hungry” regions of the world. The idea is to build the datacenters closest to the regions having the highest number of Internet users. These datacenters are called Point of Presence or POP.
Naturally, a CDN with a higher number of POPs should deliver content faster to consumers (i.e. the Internet users). Since the US is predominantly the highest subscriber to the Internet, this is why you see a higher number of datacenters (or POPs) in North America.
How does a CDN work?
In order to best understand this concept, it is essential that you understand how the basic client-server model works.
The client-server model
The client-server model is the representation of a “request-response” networking model.
- You, the client, request a website for a piece of content. Websites reside on servers, which are nothing but specialized (powerful) computers dedicated to hosting websites.
Technically, there exists a piece of software called the webserver which actually hosts your website. You might have heard of Apache, IIS, or NGINX, which are the dominant webservers powering the Internet.
Therefore, a webserver and server are two different entities. A webserver is the software aspect residing on the hardware, which is the server.
- The URL you type (say WordPress.com) is the resource identifier (also called a Universal Resource Locator) on the webserver.
- The webserver uses the URL to find the resource, which is mostly an HTML page. If the page is found, it replies or “responds” to the client.
- If the webserver is unable to find the resource, that’s when you get a “404 page not found” error.
To recap, in the client-server model, you (the client) request a page, the webserver (server) looks-up the resource and responds with the page.
How do CDNs speed up websites?
We’ve established that content is stored in a server and is served to a visitor upon request. This task is done by the webserver. Now, consider a situation where your server is located in India and your site’s visitor is from California, over 7,700 miles apart.
No matter the speed of your Internet connection, the data has to travel 7,700 miles to get to the visitors computer (or device) – which requires at least a few seconds. In order to reduce this load time and serve your content faster, websites are powered by CDNs.
The CDN copies the static content of your website pastes a copy of it in each of its POPs. When a client requests for a particular resource, the data is served from the POP that’s geographically closest to the requestor (or visitor).
This is how a CDN is used to make your site load faster.
Other Benefits of using a CDN
- Apart from drastically speeding up the load time of your website, a CDN also distributes and balances the load on your server. Your server is equipped to handle high traffic loads.
- Because the job of delivering the static request is delegated to the CDN, your server can focus on generating the dynamic content.
- Your server’s bandwidth consumption is drastically reduced, since most of the heavy lifting is done by the CDN.
- CDNs also blocks spammers, scrapers and other bad bots while protecting your website from DDoS attacks.
Who uses a CDN?
Well, almost every major website on the Internet today uses enterprise grade CDNs. Google and Microsoft have their own datacenters and hence they manage their own CDN. Websites like Facebook, WordPress.com and other high traffic websites use enterprise level CDN services like Akamai and Incapsula.
Today it’s not just limited to high traffic websites. Small websites with decent traffic also use CDNs to reap the benefits of better user experience and reduced bandwidth costs. A CDN has become more of a necessity compared to a luxury in this fast-paced world.
Will I need a CDN?
As we’ve seen from the very first section in this document, a CDN has enormous benefits to your business. If you’re running a media-heavy site, which has a lot of infographics, image aided list-style posts, etc., it is best to use a CDN from day one. This will offload most of the pressure from your hosting server and serve blazing fast images to your visitors. This would make up for a great user experience at a substantially low cost!
Keep in mind that as the traffic steadily increases, you need to move to a semi-dedicated or dedicated hosting solution as the number of requests to your web server will also increase.
As more and more websites are targeting a global audience, the popularity of CDNs is at an all-time high. At the same time, the price of the service has never been lower.
Today, with many core CDN services being offered for free, and others rented for a relatively low cost, the technology is used by websites of all sizes.
For further reading, Incapsula have a guide that goes into more depth in regard to the technical workings of CDN’s, read it here.
The choice is simple. There isn’t a red or a blue pill. There’s either a CDN or a slow site. And things are only going to get faster.