- \`command\` or $(command) - `date=$(date)` assigns output of `date` command to date variable - placing a command in back ticks or in parentheses (prepended with $) attempts to execute the output of the command ``` bash #!/bin/bash echo "test script" echo " -------linebreak-----" `date` ``` - shows an error for `date` because the output of `date` (Sat Mar 4 ...) cannot be executed ![[images/Pasted image 20250808143736.png]] - instead echoing date with back ticks ```bash #!/bin/bash echo "test script" echo " -------linebreak-----" echo `date` date echo $(date) ``` - outputs ![[images/Pasted image 20250808143852.png]] # brace expansion - iterate through all options in braces ![[images/Pasted image 20250805200816.png]]