bash → Borne again shell
bash script
bash script is a sequence of commands that can be executed by the bash shell.
shebang
Shebang (#!) specifies the location of the executable used to run the script. It must me in the first line (not considering comments, newlines and white-spaces).
If you’re not sure where the binary might be located, you can use the which command to locate the path to the executable, e.g: which bash → /usr/bin/bash. You shell will use the binaries in this path to run the script.
If you’re using bash shell, then bash is the default binary for executing shell script.
If might have seen something line /usr/bin/env sh instead of /usr/bin/bash.
You can use /usr/bin/env which returns the location of the executable.
Example:
/usr/bin/env bash # -> /usr/bin/bash