There may be several answers to this, but the one this article will touch on specifically is TLS & SSL.
These protocols apply to data when it is IN TRANSIT. You can think of in transit as: you hit the enter button after typing in your username & password into facebook.com, and a request to log in is sent to facebook.com. From the second that request leaves your computer until it gets to Facebook, it is in transit. You can imagine transmission of data happens when you click something (but can def happen more). Quite a bit of data right? TLS & SSH ensure this data in transit is encrypted.
Now the difference is SSH is more for running commands on a server, while TLS is more for sending personal information across the web. That’s it at a high level.
At a precise low level, SSH uses basic username/password authentication and TLS uses what is called an X.509 digital certificate. Did I lose you there? Hang with me…
Think of a safe where you store valuables, you need a key or code to open it right?
Same concept here. A digital certificate is to SSL what a key is to a door lock. And the same applies for SSH, except the SSH’s “key”/”code” is called an RSA key pair along with your. username/password.
It goes deeper…cryptographic algorithms are used to create the lock combinations, but I’ll leave it at this.
Know that SSH is a protocol (used in the command line window) for sending commands to other computers and TLS another protocol used for web traffic, email, instant messaging and voice over IP. SSH leverages port 22 while TLS can travel through several.
Different tools for different jobs 🙂