Solve CORS Policy Errors Between Frontend and Backend - Local Development Fix

I'm encountering CORS policy errors when my frontend application attempts to fetch data from my backend API during local development. Environment Details: - Frontend: [framework] running on [port] - Backend: [language/framework] running on [port] - HTTP method(s) causing issues: [GET/POST/etc] - Browser: [browser name] Error Message: [exact CORS error message from console] Current Configuration: - Backend CORS settings: [current config if any] - Frontend fetch/axios setup: [relevant code] - Proxy configuration: [if applicable] Requirements: 1. Need solution for local development 2. [Production deployment needs if applicable] Please provide: 1. Root cause explanation of this specific CORS issue 2. Best practice solution for my stack 3. Code implementation for both frontend and backend 4. Security considerations and production-ready approach