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

I find it useful, because when I didn't know about env, before I started to write script I was doing this:

type nodejs > scriptname.js #or any other environment

and then I was modifying that line in the file into shebang.
I was doing this, because I didn't always remember where is nodejs on my computer -- /usr/bin/ or /bin/, so for me env is very useful. Maybe there are details with this, but this is my reason