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What is the Difference Between Edge and Origin Server?

Roei Hazout
CDN Components
April 25, 2024

Edge servers are like mini data centers close to users, caching frequently accessed content from the origin server (the main content storage) for faster delivery. 

You can picture edge servers as mini libraries closer to home, holding popular books (content) for quick borrowing, while the origin server is the central library with everything.

Here is what it means for your network setup:

Origin Server

This is the heart and soul of your website's content. It houses all the original files and data that make up your webpages, like HTML code, images, videos, scripts, and databases. Think of it as a vast library containing all the books (content) that users might need.

The origin server is responsible for a multitude of tasks:

  • Content Storage: It acts as the central repository, meticulously storing all the website's building blocks.
  • Dynamic Content Generation: It's the engine that powers dynamic content creation. This includes personalized experiences like shopping carts or news feeds tailored to individual users.
  • Request Processing: When a user requests a webpage, the origin server interprets the request, retrieves the necessary content from its storage, and assembles the complete webpage.

However, geographically distant users can experience delays due to the physical distance between their location and the origin server, boosting the infrastructure’s origin streaming capabilities. 

Edge Servers

Think of edge servers as mini-data centers strategically scattered across the globe, much closer to users than the origin server. They act like caches, storing copies of frequently accessed content from the origin server.  

Imagine them as mini-libraries strategically positioned throughout a city, holding copies of the most popular books for quick access by local residents.

Here's how edge servers work their magic:

  • Content Caching: Edge servers intercept user requests and check their local cache for the requested content. If it's available (cache hit), the edge server can deliver the content almost instantly to the user's device, significantly reducing latency compared to fetching it directly from the origin server. This is particularly beneficial for static content that rarely changes, such as images, videos, and JavaScript files.
  • Content Delivery Network (CDN) Integration: Edge servers are often deployed as part of a Content Delivery Network (CDN). A CDN is a distributed network of edge servers working together to deliver content efficiently. 

By strategically placing CDN edge servers in key locations around the world, CDNs ensure content is geographically closer to users, minimizing latency and improving overall performance.

Working in Harmony

Edge servers and origin servers operate in a beautiful synergy to optimize content delivery, thus eliminating the need for a CDN vs edge computing debate. 

Here's a breakdown of their collaborative effort:

  1. A user initiates a request for a specific webpage.
  2. The closest edge server intercepts the request and checks its local cache for the requested content.
  3. If the content is found in the cache (cache hit), the edge server delivers it directly to the user's device, resulting in a faster loading experience.
  4. If the content is not found in the edge server's cache (cache miss), the edge server acts as a messenger, fetching the content from the origin server. Once retrieved, the edge server might cache the content locally for future requests from users in the same region.
  5. The origin server processes the request, generates any dynamic content, and delivers the complete webpage to the edge server.
  6. The edge server then forwards the complete webpage to the user's device.

Collective Benefits

By working together, edge and origin servers unlock a multitude of benefits for you:

1. Faster Loading Speeds

By keeping frequently accessed content closer to users, edge servers significantly reduce latency and improve website loading times, especially for geographically dispersed audiences. 

This translates to a more responsive and engaging user experience.

2. Reduced Load on Origin Server

Edge servers act as a buffer, absorbing a significant portion of user requests. This alleviates pressure on the CDN origin server, allowing it to focus on processing complex tasks like generating dynamic content and handling database queries. 

3. Improved Scalability and Performance

The distributed nature of edge servers allows websites to handle high traffic volumes more efficiently. During peak usage periods, edge servers can handle a substantial portion of the traffic load, thereby preventing bottlenecks at the origin server. 

This setup enhances the scalability and performance of the network, allowing it to accommodate growth and spikes in user demand without degradation of service.

4. Optimized Bandwidth Usage

Since edge servers cache and serve static content locally, they reduce the amount of data that needs to be transferred from the origin server. 

This decreases bandwidth consumption and can lead to cost savings, especially when dealing with large files like videos and high-quality images.

5. Enhanced Security

Through distributing the points of access through edge servers, the risk of direct attacks on the origin server is mitigated. 

Edge servers can provide additional security measures like DDoS attack mitigation and traffic filtering, which shield the origin server from potential threats.