Rodrigo Fernández, a full-stack JavaScript developer and Ionic contributor, discusses the challenges and solutions related to Cross-Origin Resource Sharing (CORS) errors in Ionic apps, which are built using web standards like HTML, CSS, and JavaScript, and can be deployed as Progressive Web Apps or native apps using Cordova or Capacitor. He highlights that Ionic apps, running in a browser or webview, are protected from common security threats such as Cross-Site Request Forgery, and explains that CORS is a security measure that restricts HTTP requests to resources from different origins unless the server provides the necessary headers. Fernández notes that CORS errors occur when servers do not return the required headers, causing the browser's Same Origin Policy to block requests, and emphasizes the importance of understanding and configuring CORS correctly to ensure app functionality across various platforms. To address common CORS-related questions and issues, he has compiled a new section in the Ionic documentation to guide developers in troubleshooting CORS errors and implementing best practices for different scenarios.