Learn how to set up a Linux Ubuntu server, configure SSH keys, and deploy a MERN (MongoDB, Express, React, Node.js) application using PM2 process manager and Nginx reverse proxy. Follow step-by-step instructions to create a server, generate SSH keys, connect securely, upgrade packages, and create a new user with enhanced security measures. Install Node.js, clone your application, set up MongoDB, configure environment variables, and manage dependencies. Implement PM2 for process management, configure firewall settings, and install Nginx as a reverse proxy. Finally, learn how to set up a domain name and secure your application with SSL.