Once upon a time in a peaceful online world, there was a powerful wizard named Website Wizard and a friendly dragon named Data Dragon. Website Wizard lived in the magical kingdom of “website.com,” while Data Dragon lived in the kingdom of “api.com.”

Before CORS:

In the early days of the internet, websites were like isolated kingdoms. Each website had its own set of resources (like images, scripts, and data) stored within its domain. It was relatively simple because a web page could freely request and load resources from its own domain without any restrictions. However, problems arose when websites wanted to fetch resources from other domains.

Imagine a world where each kingdom had high walls and gates that only allowed their own residents to freely enter and exit. This setup worked fine until websites wanted to share or access resources from other websites, like embedding a video from another domain or making an API call to fetch data. They faced challenges because the security gates were firmly shut to prevent unauthorized access. This lack of access control led to security vulnerabilities, like cross-site request forgery (CSRF) and cross-site scripting (XSS) attacks.

Introduction of CORS:

To address these security concerns, web developers and browser makers came together to create CORS (Cross-Origin Resource Sharing). CORS introduced a set of rules and headers that allowed websites to request and share resources securely across different domains. It’s like building a diplomatic channel between the kingdoms, where they can communicate and exchange resources peacefully while still maintaining security.

During CORS Transition:

Now, Website Wizard wanted to make his website even more amazing by getting some special information from Data Dragon’s kingdom, like the latest news and weather updates. However, the security gates were still firmly shut at this point.

Website Wizard realized that to make this happen, he needed to implement CORS. He consulted with his magical tech-savvy advisors, who helped him understand the importance of CORS. He cast a spell on his server, configuring it to send CORS headers, granting Data Dragon’s kingdom permission to access the resources it needed. It was like creating a treaty between the two kingdoms, allowing safe resource exchange.

After CORS:

With CORS in place, the online world became more interconnected and secure. Websites could now request and share resources from other domains, but only if they had permission. This permission was granted through HTTP headers sent by the server, indicating which domains were allowed to access their resources. For instance, Website Wizard’s server could specify that Data Dragon’s domain was permitted to access its information.

This made it possible for Website Wizard to send Browser Bird to collect the latest news and weather information from Data Dragon’s kingdom. The CORS guard at the border, instead of blocking Browser Bird, saw the permission slip (the CORS headers) and allowed the safe passage of data between the two domains.

So, after CORS, the online world became more interconnected and secure, allowing websites to share and access resources from different domains while preventing unauthorized access and security vulnerabilities. It brought about a new era of collaboration and information exchange on the web.