What is the difference between Telnet, SSH and FTP? I understand last two but Telnet is what am having issues with.

In my understanding, SSH is what we use to connect to a remote server (it can be a normal computer as well with ssh enabled) and get access to the terminal like we get while using a physical machine. Secure.

In FTP, we can transfer (upload and download both) files to/from our local machine to the server. Not secure.

In short, in SSH we get a secure shell on our remote server while in FTP we only get the ability to transfer files and they are not transmitted through secure medium.

I hope am correct till now, if not please feel free to correct me.

Now can anyone please explain telnet comparing these two?