Display information about Bash builtin commands.
# To display the full list of builtin commands:
help
# To print instructions on how to use the 'while' loop construct:
help while
# To print instructions on how to use the 'for' loop construct:
help for
# To print instructions on how to use '[[ ]]' for conditional commands:
help [[ ]]
# To print instruction on how to use '(( ))' to evaluate arithmetic expressions:
help \( \)
# To print instructions on how to use the 'cd' command:
help cd