CDN is a network architecture that serves from different geographical locations, allowing websites to respond to requests more quickly and with less resource consumption. Websites with a high volume of visitors use CDN services. Requests made to a website using CDN are answered by the server closest to the website visitor instead of the main server. This reduces the loading times for web page files.

What is CDN?

CDN is an infrastructure that enables the distribution of web content with high internet traffic. It stands for ""Content Delivery Network."" Within this network, there are interconnected servers deployed in different locations. When a visitor wants to access a webpage on the internet, they travel through the network. With CDN, the webpage is served from the server located closest to the visitor, reducing the journey time on the internet.

How Does CDN Work?

CDN operates with a caching system. Web content is stored not only on the main server but also on servers in various locations around the world. When you enter a website's name in an internet browser, query processes occur within the internet network. In a system without CDN, the server hosting the website responds to these queries, sending the webpage's content to your computer.

If CDN is used, the content is sent from a nearby server where a copy of it has been cached earlier. CDN servers keep a cached version of pages that have been accessed at least once. If the content changes, CDN compares it with the main server at set intervals to update it. A website supported by CDN, alongside modern web architecture, has a high-performance infrastructure, increased data security, scalability, and operates on a predictable system.

What Does CDN Do?

CDN has various functions to improve website performance and accessibility. Let's take a closer look:

• Increases site speed: If a visitor from Germany visits a website in Turkey without CDN, the time taken is longer compared to a site with CDN. With CDN, background requests are sent to a server closer to Germany instead of Turkey, reducing the time.
• Improves data security: CDN keeps SSL certificates that encrypt website traffic updated, ensuring that visitor data on the website is protected at a security level.
• Provides active protection against attacks: CDN protects against attacks that could affect the website's operation, such as DDOS and password attempts. It can filter traffic based on the source of the attack and block it when needed.
• Filters traffic: CDN can detect unnecessary traffic like bot traffic and filter it out if desired.
• Monitors traffic 24/7: CDN tracks the total MB traffic of your website and identifies which locations it comes from.
• Keeps the website accessible: In case of planned or unplanned main server outages, CDN can serve cached content to keep the website accessible. This means that even if the main server is down, visitors can continue to access the website through CDN. The site administrator is notified of such events in real time.

However, as CDN servers serve websites through caching, changes on the main server do not instantly reflect on CDN servers. In such cases, manual cache clearing might be needed. Additionally, the CDN system can be temporarily disabled, allowing for rapid adjustments. It can also be reactivated when desired."