/etc/shadow
From Linuxintro
/etc/shadow is a file that contains encrypted passwords for the users listed in /etc/passwd. It can look like this:
root:$2a$10$nAu/t6aigNE1RpgshyXFSO8heERwSFJqAGxUch8fXe5sJFxs.aqp2:14903:::::: bin:*:14749:::::: daemon:*:14749::::::
The columns are separated by colons. The first column contains the user name. The second column contains the password.
