CDN explained for beginners

What is CDN?

CDN is the short acronym for Content Delivery Network, and it represents a large network of servers that are spread across different geographical locations. The main purpose of these servers is to cover a territory well and provide fast answers to the requests of potential users. All of the servers store the needed information, like images, video, code, in their cache memory. Additionally, they aim to be as close as possible to the users. As a result, the service is way more improved and quicker. Moreover, an extra positive effect of the CDN is load balancing. It improves the performance and reduces the load on the primary server.

How does it work?

The idea behind CDN is actually pretty simple. There are DNS recursive servers that examine from where the DNS request is actually coming. Afterward, they provide to the user the IP address of the server, which is located as close as possible. Oftentimes some service providers call these cache servers delivery nodes.

As we mentioned, the DNS servers are placed in very strategic locations. You are able to choose as many as you need and set even more in regions that are important. However, that depends on your DNS provider.

Compared to Anycast DNS, where the network of DNS servers holds an identical IP address, in the case of CDN is commonly used a GeoDNS service, also known as Traffic Director. This service allows you to use separate IP addresses for different locations. 

Thanks to that, all of your traffic won’t overwhelm the very same source. Additionally, you can set a second web hosting in the crucial locations. The servers are going to store the data in their cache memory, and you can set their IP addresses for the closest DNS server. The DNS request is going to receive a fast answer from the available and near cache server.

How to build your CDN?

You can create your CDN by having the following things:

  • Domain name/subdomain
  • Minimum of two servers in different locations. They could be dedicated or virtual.
  • GeoDNS tool for directing the users’ requests to the nearest server.

Advantages of CDN

It improves the loading time and minimizes latency. – That is possible due to having a server with the cached data nearby the users who initiate the requests. That allows the transfer and the loading process of images, videos, HTML pages, and other items to be extremely fast. The speedup of the loading time positively affects the user experience and SEO.

CDN improves your availability and redundancy. – The extensive CDN network with servers storing the data is extremely beneficial. In situations when a particular server is down, your website and content are still going to be available for your visitors. 

It improves security. – Extensive networks effectively spread malicious traffic when a DDoS attack is initiated towards your website, for instance. In addition, you can implement a DDoS protection service offered by some of the DNS hosting providers. 

Less bandwidth – The cached data allows your primary server not to deliver constantly identical content over and over again. Thanks to that, the amount of data transferred from your website’s host server is minimized.

SaaS, PaaS, IaaS – Everything you need to know

SaaS, PaaS, and IaaS are the primary three types of cloud computing as-a-service choices. Every one of them covers a different level of management for you. So, let’s explain a little bit more about SaaS, PaaS, IaaS, and cloud computing and how you can use them to build an environment that satisfies all of your needs.

Cloud computing – definition

Cloud computing is an on-demand supply of various computing services or resources through the Internet in exchange for a defined fee. That way, you can get all the things you need, such as data centers, servers, storage, databases, software, security, really quickly and without the necessity to actually own them.

For sure, cloud computing entirely changed the model of receiving these services. It lowers the operation costs of many customers because they are not required to purchase and maintain data centers and numerous services. 


SaaS stands for software as a service additionally called cloud application services. It provides a complete application that is managed by a provider via a web browser. The customer receives software that is ready to use. As a customer, you are not able to make any modifications to the particular software, and you receive the features which are included in the specific plan you chose.

On the other hand, the provider of SaaS has the responsibility for networking, storage, servers, virtualization, OS, middleware, runtime, data, and app. In addition, it is responsible for taking care of and maintaining errors, bug fixing, software updates, and generating new features.

  • Advantages: It is very easy to start implementing it and also to use it. Additionally, you are not required to maintain any of the services.
  • Disadvantages: You don’t have any control over the software and the development. Additionally, these services are vendor lock-in. As a result, it is more difficult to migrate to another provider.
  • Examples: Dropbox, Microsoft 360, Skype, Google Apps


Platform as a service, or shortly PaaS is a great option for development. This cloud computing type of service supplies you with networking, storage, servers, virtualization, operating system (OS), middleware, and runtime already operating smoothly. That gives a chance for developers to start writing code directly. When you start implementing PaaS, you are answerable for all of the data and the various apps which you are going to need. 

  • Advantages: It is easy to use due to the fact that almost everything is pre-installed. You only have to select the needed applications and start operating with them. Additionally, you are not concerned about taking care of the operating system (OS) or the infrastructure.
  • Disadvantages: A single PaaS provider may not support everything that you want. Additionally, the provider is responsible for the storage. Therefore, it could not be absolutely secured.
  • Examples: Microsoft Azure, Amazon AWS, Google Cloud, Heroku


Infrastructure as a Service, or shortly IaaS, is going to provide you with an open canvas. The provider of this service is accountable for taking care of the infrastructure, meaning networking, storage, servers, and virtualization. The customer is left to take care of the middleware, runtime, data, operating system (OS), and apps.

It is a perfect opportunity when you want to go to the cloud and leave behind the on-premise server.

  • Advantages: It is a way cheaper option compared to a local server. Additionally, any infrastructural issues are not your concern.
  • Disadvantages: You still have to maintain the system and the software.
  • Examples: Rackspace, Amazon AWS, Microsoft Azure, Google Cloud


These three types of cloud computing, SaaS, PaaS, IaaS, are really great. Make sure to choose the type of service which is going to suit your needs the most.