what is SSH (Shell Access) ?

can somebody explain me what it is and for what it is.

SSH is a secure network protocol.
Whenever bits are sent by a computer to the network, SSH automatically encrypts it. Then, when the data reaches its recipient, SSH decrypts it. The great result is that this is transparent encryption: users can work normally, unaware that their communications are safely encrypted on the network.

Its best features are:

• A secure, client/server protocol for encrypting and transmitting data over a network
• Authentication (recognition) of users by password, host, or public key, plus optional integration with other popular authentication systems, such as PAM, Kerberos, SecurID, and PGP
• The ability to add security to insecure network applications such as Telnet, NNTP, VNC, and many other TCP/IP-based programs and protocols
• Pretty good transparency to the end user
• Implementations for most operating systems

You could use the free software Putty to create a SSH connection with your hosting space and manage your files and directories like local ones.

thx for the answers,
i have asked because some host companys have it enabled and some not for their hosting plans

Not for noobs. SSh is the basic way to control / manage remote servers at root level on the command line, typically UNIX. Of the 40/ 50 servers and hosting companies I use, only 1 had VNC as default. The other ones use SSH. It is much more secure than telnet and can also be used in combination with ftp on ssh. Note that shared hosting can't have it, at least surely not at root level. It is typical on VPS and Dedicated.