What is CDN?

CDN is the abbreviation of Content Delivery Network, which means "Content Delivery Network". Generally, what we call CDN acceleration generally refers to website acceleration or user download resource acceleration.

CDN is a layer of intelligent virtual network formed on the basis of the existing Internet by placing node servers all over the network. The CDN system can redirect the user's request to the service node closest to the user according to the comprehensive information such as the network traffic and the connection of each node, the load status, the distance to the user and the response time in real time.

The core purpose of CDN is to enable users to access the network nearby, obtain the required content, solve the situation of network congestion, and significantly improve the response speed of users visiting websites or the download speed of users.

To put it simply, CDN is acceleration. When a website has CDN acceleration enabled, it gives users the impression that the speed of accessing the website or downloading things will be significantly faster than if the acceleration is not enabled, and it will become faster or download things faster.

Why is it faster for a website to open CDN user access? Because CDN distributes the content of the source site to all nodes in the country, it shortens the delay for users to view objects, improves the response speed and availability of users accessing the website, and solves the problems of small network bandwidth, large user visits, and uneven distribution of outlets.

To put it simply, when a website opens CDN, users access the website, not directly to the original server of the website, but a server node distributed by a server closest to you. Since the server is close to you, the access speed or download speed will be faster.

In fact, it is easy to understand. For example, why is it slow to visit foreign websites in China? The main reason is that the distance is too far. The mission of CDN is to store website content on CDN nodes all over the country and even around the world. When users visit the website, they can obtain the content cached on the CDN nearby, thereby improving the access speed.


Reprinted from Jiangsu Sanai Network