What is the difference between “#!/usr/bin/env bash” and “#!/usr/bin/bash”?

Question

In the header of a Bash script, what\'s the difference between those two statements:

1. #!/usr/bin/env bash

2. #!/usr/bin/bash<

Answer 1

Using #!/usr/bin/env NAME makes the shell search for the first match of NAME in the $PATH environment variable. It can be useful if you aren't aware of the absolute path or don't want to search for it.