The primary difference between SSH (Secure Shell) and RDP (Remote Desktop Protocol) is the user interface and the target operating system they are designed to connect to.      

S SSH is built for text-based terminal access. When you connect to a Linux EC2 instance via SSH, you interact with the system purely by typing commands. It relies on a public/private key pair for authentication, making it incredibly secure and standard for DevOps and server administration.   

R RDP is built for a visual desktop experience. When you connect to a Windows EC2 instance via RDP, you see a full virtual desktop where you can use your mouse, click icons, and open windows. To get the administrator password for an RDP connection, AWS requires you to decrypt the initial password using your
private key file.