CDN vs Caching: How They Both Are Different In Work?

Mark Smith
6 min readJul 15, 2020

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CDNs (Content Delivery Networks) are geographically created and distributed networks consisting of proxy servers with an aim to serve content more quickly to the users accessing the internet via that server.

CDNs goal is to provide high content availability and increased performance simply by distributing the best information delivery services to the end-users. The term CDN came in the late 1990s to alleviate internet performance.

On the other hand, Caching is simply a process of storing information in a computer. It is an impactful thing that a content publisher uses to improve the speed and performance of a website.

With the help of caching, the publisher stored the content on the internet such that it can be easily accessed by anyone. As a result, this reduces the visitor’s time to access the website data!

You might think that the CDN and Caching both are the same, but it is not true! There are a few differences between CDN and Caching. Thus, in this article, we are going to detail out all the differences by comparing CDN vs Caching.

The tech giant Google always emphasizes on the website speed because the site speed greatly impacts the SEO. To get better SEO people always embrace easy ways of increasing site loading speed, decreasing site loading time.

In recent years, there has been a sudden explosion of caching plugins, caching widgets, CDN services in the market. All of these promises to speed your website.

If some choose CDNs, then some would choose caching! There is a great difference between Caching vs CDN services. Therefore whatever a publisher chooses impacts will be on the website!

What publishers and online companies don’t realize is that the website speed services like CDN and caching can also put opposite impacts on the website.

Hence, if you are able to know the similarities and differences between caching and CDNs, then you can avoid bogging your website.

“The one significant difference between CDN vs caching is that CDNs can perform caching. However, everything performing caching cannot be termed as a CDN.”

Working Of A CDN

A CDN is a network made of proxy servers to cache website content present in multiple locations. The CDNs goal is to deliver the content efficiently. A content delivery network acts as a layer between the user or reader and the server.

As a result, a CDN prevents the requests going to the same server. The proxy servers in CDN are able to distribute requests across the globe with respect to the end-users.

“Today, a few top popular CDN services are Cloudflare, Akamai, and MaxCDN (now also known as StackPath).”

Cloudflare is able to add an additional caching layer such that you can have caching on your website, on a user’s browsers, and servers. If a user has visited your site before, then an updated page will be at the user-end. This is the basic rule of caching!

This means that the request has been sent to the original server! This way the Cloudflare CDN service is also known as CDN cache (CDN + Cache).

Suppose that the user is in Raleigh, USA and the origin server is located in Singapore. Now, the user’s content request will take a long time to travel between both locations.

However, if you use a CDN then you can easily retrieve the content from any site whatever is the location. Furthermore, every time you retrieve information the website is updated.

As the site is updated, caching is easier and is done at the closest to your server location. This reduces the load time for the upcoming visits.

“Typically saying, we can call A CDN a type of caching.”

More specifically, Cloudflare uses edge cache. It means caching static assets (such as images, CSS, JS) at the network’s edge to decrease the trip to the end-users and speeding the delivery of content by lowering the server load.

“Like the edge caching, some CDNs will also cache page content.”

Working Of Caching

Page caching, in other words, is also known as HTTP/HTTPS caching or website caching. In this, caching stores data like images, videos, web pages, etc. when such content is loaded for the first time.

The data storage is done in the unused RAM portion which doesn’t put any significant impact on the memory. As a result, if the user visits the site again, then the content loads quickly.

Page caching is always limited because it is able to communicate only to store and save data. Therefore, the publishers or the content creator has to set caching rules so that the visitors can see fresh content every time they visit the website.

This way, the web pages which aren’t changed for a long time, will serve from the cache. Thus, the images, videos, and other forms of content upon updates are left to get cached for the later visits.

This kind of caching happens in WordPress. Publishers simply install caching plugins like WP Rocket, W3 total cache, etc. and cache the content present on the website.

However, if the caching rules aren’t set correctly, you may put your site in the category of slow and sluggish versions of the websites. Hence, the following caching rules are necessary!

Unlike the page caching, browser caching simply makes the user experience on the website very fast whenever the user visits the site regularly. Browser caching is page caching!

Instead of the required data requests and sends, the major need is to display the webpage on your browser. What if the webpage is forced to be stored on your computer?

Now, if somebody visits your website on a browser, they easily get cookies. The only rules here you have to set is “the content shouldn’t be changed, the visitor must visit the same browser, and the visitor must have a previous history of browsing the same website.”

This would make the web page load instantly and would also produce a cached version of the page. In a browser cache, a group of files and content is stored for later use. This includes:

• HTML/CSS pages
• JavaScript
• Images/Multimedia

As a result, the users can change and set the caching settings within their browsers such as Google Chrome, Mozilla Firefox, Microsoft Edge, Apple Safari, etc.

Websites are able to communicate with browsers. Thus, if a web page is updated, the browser replaces the old content with the new content and saves the new content!

CDN Vs Caching: What Are The Differences?

It is important to find out the difference between CDNs and caching. Though they both share the user experience on the fast and more seamless website,

The caching occurs only when you use a type of CDN service. As the CDNs are reverse proxies between the user and origin server, the caching speed will be higher rather than using the speed optimization plugins.

Caching Plugins and CDN services have in-built nature to transfer information at multilocation. However, the plugins are slower!

But the caching at the CDN-level is close to the origin server, thus, makes fewer requests. As a result, it increases the website metrics at TTFB and increases the speed of providing good user experience.

Wrapping Up Their Working

Caching stores static content when the first request is served to the users at some location. This is an in-built HTTP/HTTPS feature.

On the other hand, CDN enhances the end user’s internet experience by utilizing its own servers and the end-users servers called Edge Servers.

Therefore, we can say that -

Caching is part of CDN. Caching utilizes CDN to accelerate the internet!

CDNs make use of multiple mechanisms and make internet experience better for all the online users.

What Should I Use From CDN vs Caching?

If a user requests content/data from a website that uses a CDN, the CDN fetches that content from the original server and saves a content copy for future requests. As a result, the cached content will always be present in the CDN unless the users request it continuously.

The CDN caching servers are multi-located all over the globe. A data center is a location where CDN servers are present. Whenever a website responds to CDN servers of the requested content, you would come to know how long to store it.

Therefore, both CDN and caching serve the same purpose of storing content forever on the internet. But caching is a part of CDN and caching works slower than the CDN services.

You can think of CDN as a chain of proxy networks that travels the content much faster, closer, and stores information every time a user visits. The mechanism with which a CDN is able to do so is caching.

Hence, caching and CDN both are incomplete without each other though they are entirely different in working. We can call CDN and caching the same, but CDN performs caching, but the vice-versa is not true.

If you have some further doubts about this then don’t forget to ask them in the comment section below. We would be able to answer them as soon without any problems!

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Mark Smith

professional tech writer who writes at globally ranking websites & blogs. With 10+ years of experience website development and web designing Services.