What is Bash shell?

Bash stands for Bourne Again Shell. It is free software written to replace Bourne shell.

We can see following line in shell scripts for Bash shell.

In Bash we use ~/.profile at login to set environment variables.

In Bash we can execute commands in batch mode or concurrent mode.

In batch mode commands are separated by semi colon.
% command1; command2

In concurrent mode we separate commands by & symbol.
% command1 & command2