What is SSH?
It is a protocol suite tool that connects various networks and encrypts traffic accordingly such as password access, log-in details, etc. to keep it safe from all kinds of attacks. In a telnet session, the password is passed across the Internet which is yet unencrypted.
There are two versions that are available at present –
a) SSH1
b) SSH2 (FTP Supported)
There is also an alternative that was developed by the OpenBSD project. It is completely accessible with SSH1 and SSH2. However, it is based upon OpenSSL. All the latest Linux versions are packaged with OpenSSH as well as OpenSSL