i know that /dev/null is used redirect output of commands in shell scripts to a null device so the user won't see a lot of output when running certain scripts.
here is my question: what is the difference between these two command?
ls -l /etc | grep resolv.conf > /dev/null
ls -l /etc/ | grep resolv.conf > /dev/null 2>&1
i just want to understand what 2>&1