Unix shell is a command-line interpreter that gives you user interface for the Unix operating system. When the user logs in to the system the shell program is automatically executed.
Here is the best way to find out what shellyou are using.
you should receive confirmation of the type of shell you are running, like sh, ksh, csh, tcsh, bash or zsh
.profile is the shell startup file, like autoexec.bat is the startup file for DOS users; .profile will get executed whenever you login. It is used to set environment variables and shell options such as $PATH
In ksh (Unix Korn shell) .profile will be in each home directory of each user.
For example :
Using SSH / Telnet client, you can connect and log in to a remote machine (your Virtual Server) from anywhere in the world, as if you were sitting right in front it.
SSH client is a software program which uses the secure shell protocol to connect to a remote computer. IN SSH you can use all commands used in Telnet client. The only difference is that the communication is made via encrypted channels to and from your Virtual Server.
Unix is not an acronym; In 1969 Ken Thompson wrote the first version of Unix, called UNICS. The name “Unix” was intended as a pun on Multics (and was written “Unics” at first — UNiplexed Information and Computing System).
Unix is a powerful, multi-user environment. Unix was developed at Bell Labs in 1969. Examples of Unix implementations include Mac OS X/Darwin (Apple), GNU/Linux, AIX (IBM), Solaris (Sun), IRIX (SGI), and FreeBSD.