A CDN (Content Delivery Network) should be used for several reasons:

1. Faster website loading times: By storing website content on servers distributed in different locations worldwide, a CDN can deliver the content from the server closest to the user. This results in faster website loading times and better user experience.

2. Improved website availability: CDNs can help to improve website availability by reducing the load on a website's main server and distributing the traffic across the network. This can help to prevent website crashes or downtime during periods of high traffic.

3. Global reach: A CDN can help websites to reach a global audience by delivering content from servers located in different regions worldwide. This can help to improve website performance for users located in different parts of the world.

4. Better security: Some CDNs offer security features such as DDoS protection and SSL certificates, which can help to protect websites from security threats.

5. Cost savings: Using a CDN can help to reduce the bandwidth and storage costs associated with hosting a website, as the content is stored and delivered from the CDN's servers.

Some things to consider when choosing a CDN: Network: A larger CDN (more PoPs) can provide better performance.

Performance and Reliability: Enquire about the CDN’s performance and uptime. Security: Choose a CDN that offers security features, such as DDoS protection, web application firewall (WAF), and SSL/TLS encryption. Support and budget: Choose a CDN that’s within your budget, and customer support is always a good idea.

Overall, using a CDN can help to improve website performance, availability, and security, while also reducing costs. It is a valuable tool for website owners who want to provide the best possible experience for their users.