Definition
A Content Delivery Network (CDN) is a geographically distributed network of proxy servers and data centers. It aims to provide high availability and performance by distributing the service spatially relative to end users. CDNs emerged in the late 1990s to address Internet performance bottlenecks as it became an essential medium for communication and commerce.
User Cases
CDNs are widely used to serve a large portion of Internet content, including text, graphics, scripts, downloadable objects like media files, software, and documents, as well as applications such as e-commerce portals, live streaming media, on-demand streaming media, and social media services. Content owners, such as media companies and e-commerce vendors, pay CDN operators to deliver their content efficiently to end users.
Why It Matters for SEO
CDNs are crucial for SEO because they help reduce page load times, which is a significant factor in search engine rankings. By distributing content closer to users, CDNs minimize latency and improve user experience, which can lead to lower bounce rates and higher engagement. Faster websites are favored by search engines, thus enhancing the site’s visibility and ranking.
Related Concepts
Related concepts include edge servers, which are part of the CDN infrastructure that serves content to end users, and origin servers, which are the original source of the content. Other related terms are load balancing, which helps distribute traffic efficiently across servers, and Multi CDN, which involves using multiple CDNs to optimize performance and reliability. Additionally, CDNs often overlap with services like DDoS protection and web application firewalls (WAF).