Apache Question:

htpasswd is used for allowing user to authenticate for a
particular web page. such as you are running 2 or more web
pages through virtual hosting or any other method and want
to provide access for any user to access a particular page
with authentication then you can use the htpasswd for
creating user authentication file. when you run the command
htpasswd with the option -c and -m for any user it will
create a file named htpasswd in which an entry for user name
and encrypted passswd will create.