What is </dev/null in bash?

Question

In bash, standard (1) and error (2) output can be re-routed and discarded with:

>/dev/null 2>&1

But the following example does s

Answer 1

It is a way to close stdin, as if EOF (^D) were sent to it. It can be used as in this example with the mail command to signify it that the command should no more expect input from stdin.

It is also often used to daemonize processes (Stop 6 of the recommended approach for creating well-behaved daemons)