CDN stands for Content Delivery Network, which is a system of distributed servers designed to deliver web content more efficiently. CDNs cache static assets like images, videos, and stylesheets across multiple geographic locations. When a user requests content, the CDN serves it from the nearest server, reducing latency and loading times, which enhances user experience. Additionally, CDNs improve website reliability and performance during high traffic, protect against traffic spikes, and can provide security features, such as DDoS protection. This technology is essential for modern web performance optimization.