What is CDN? What is cache? How does CDN work?

In today’s topic, we will be sharing all important information about CDN. By reading this article we will know What is CDN? What is cache? How does CDN work?

What is CDN
What is CDN? What is cache? How does CDN work?

Just as slow internet speed is a cause of annoyance, slow website speed is a curse, because if the website is slow, it causes annoyance to the user.

They move to alternative websites so that the real purpose of the website is not achieved.

This reduces the income from the website and the website drops in the search engine rank.

We try many things to protect our website from all these problems. Many ask to change hosting or optimize website speed.

However, the loading speed of any website can be easily increased several times without changing the hosting.

In today’s post, we will learn about what CDN is and how it works.

What is CDN?

CDN stands for Content Delivery Network. In short, CDN is a system that delivers content to the user.

In a nutshell, CDN is a system that looks a lot like a web server but does not store files like a normal server.

General servers store the physical files of the website which we see from different websites. But the CDN website shows the same file but from their own geological server.

In other words, when a website uses CDN, when you visit that website, you will see a copy of that website which is cached from the main server.

When you request a page to be viewed in a browser, that request finds a CDN server near your location. Find the server and show your requested page from there.

Finding a server near you here makes your internet speed slow but the page loads fast. The matter will be more easily understood if it is discussed more clearly.

Suppose you have a website hosted on a server in England. But all your visitors come from Asia.

So if someone wants to see your website, after sending a request to the browser page, it will go to England after crossing many roads and will show that page in the browser after covering the same distance.

We know that data is exchanged on the Internet through light.

Various studies have shown that no communication signal can ever go faster than the speed of light.

Internet data speed from here but limited. Due to this limited speed, the greater the distance, the lower the speed.

But if the same website comes to your user’s location, it can be shown in the browser from any server nearby, but the page will load much faster. CDN technology was invented with this in mind.

What is cache?

The temporary storage folder is called cache in the language of the Internet. For example, when we visit a new website, a temporary folder is created in the browser installation folder.

Where all the data of that website is downloaded. The next time you visit that website, the resource is brought from that folder and shown in the browser.

In the language of the internet, cache means downloading a full copy of a website.

The advantage of caching is that it does not require frequent downloading of website resources, it loads website resources very quickly.

The CDN technology system downloads full website files from the main server in this way and stores them on each of the local CDN servers.

When something new is added to the website, it caches each CDN server and updates the data in the caching server.

How does CDN work?

CDN usually works in three ways. The PoPs or Point of Presence method is used here to bring the content closer to the visitor.

This means that many caching servers are built together, much like a data center.

Each data center is set up in different countries of the world, thus reducing the entire path of file exchange.

Then each caching server uses CDN to cache each website. Due to the presence of servers in different countries, if you visit the website from any location, the page loads from the server near that location.

This reduces the loading speed of the website. Similarly, the bandwidth is greatly reduced.

Cacheing servers are usually built with SSD, HDD, or RAM. However, all current servers are made with either SSD or RAM.

Because in SSD and RAM file read and write is much faster. Most of these servers are made by RAM. Because RAM can read and write files faster than SSD.

CDN works in these three ways. To use CDN you need to get service from any CDN provider, such as Cloudflare.com

You can use the CDN service either free or paid. CDN can be used on all types of websites like Blogger, Weebly, WordPress, and all other fields.

However, the setup in WordPress is much easier. To activate the CDN on the website, the domain and the original website have to be configured from the database.

The domain has to use a CDN nameserver so that if someone wants to visit the website, the CDN nameserver is detected and taken to the cache server.

CDN Security

There are many CDN services that provide other security services including SSL. For example, Cloudflare provides SSL service for free.

Also, because it is a cache server, even if it attacks your website, it doesn’t work. Because your site does not operate from a dedicated server, the attack does not work properly.

However, using CDN does not mean that your website will never be hacked.

Between September 2016 and February 2017, Cloudflare.com suffered an attack called “CloudBleed HTTPS traffic leak“.

This led to the leak of data from about 7 million Cloudflare CDN-used websites. The main reason behind this is that CDN uses a shared network connection.

In this way, if you get network access in any way, you can take access to all the websites in that network.

Advantages and disadvantages of CDN

Advantages of CDN

  • Fast website loading speed
  • Reduces bandwidth costs
  • Fast content is guaranteed
  • Improves website security
  • The whole world can be reached quickly
  • Local cache  servers all over the world can be used for a small amount of money
  • Website is always online 24/7
  • Reduces server load time
  • Detailed analytics data is available on the website
  • Minifying files can save storage on the server

The disadvantage of CDN

  • Uses shared network connections
  • Proxies or VPN connections often block the site
  • Cash servers have not been fully distributed in every country of the world so far
  • Website management is a bit complicated


1. Do I have to use CDN?

Using a CDN depends on your needs. Suppose you have an affiliate website and its targeted visitors are from the US.

Now you don’t have to show that website all over the world. In that case, you will no longer need to use a separate CDN if you have server storage located in the US.

2. Is CDN just for WordPress?

CDN for all types of websites. There are no special rules here. You can use CDN on any CMS or website without CMS as per your requirement.

3. Can CDN be used for free?

Yes, CDN can be used both free and paid. However, the work is done for free. But in order to use the advanced feature, you have to use paid.

4. Is CDN secure?

Yes, CDN is a secure system. CDN system security and user experience are improving with the advancement of technology.


The world’s largest websites use CDN to cover the whole world. If you have an international website, it would be wise to use the CDN service.

In addition, if the website has a lot of visitors, then CDN is important to handle these extra visitors.

Hopefully, by now you have a clear idea about CDN. If you have any questions about CDN, please let us know in the comment box. Thank you.

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