What is SSH?
SSH (Secure Shell) is a program that lets you connect to another computer over the internet and control it as if you were sitting right in front of it. It does this safely by encrypting everything you type and receive, so nobody can eavesdrop.
Let's break it down
- Secure: protected from spying or tampering.
- Shell: a command-line interface where you type text commands.
- Connect: open a link between your computer (the client) and a remote computer (the server).
- Encrypting: turning data into a scrambled code that only the two computers can read.
Why does it matter?
Because it gives you a safe way to manage servers, run programs, and move files without exposing passwords or data to hackers. It’s the backbone of most remote administration and DevOps work.
Where is it used?
- System administrators log into web servers to install updates or fix problems.
- Developers push code to cloud machines or containers during deployment.
- IT support staff troubleshoot users’ laptops remotely.
- Automated scripts use SSH to copy backups between data centers.
Good things about it
- Strong encryption keeps the connection private.
- Works on almost every operating system (Linux, macOS, Windows).
- Can forward other network traffic (port forwarding) for secure tunneling.
- Supports key-based authentication, which is more secure than passwords.
- Lightweight and fast, using little bandwidth.
Not-so-good things
- Requires proper key management; lost or stolen keys can be a risk.
- Misconfiguration can leave ports open to brute-force attacks.
- Only provides command-line access by default, which can be intimidating for beginners.
- Does not encrypt the entire network stack; other services may still need separate security measures.