The Password Protect Directories feature, that's located on your website's Control Panel, allows you to set a password to limit access to your website (or parts of it).
From "Select Directory" table, you can select the directory you wish to protect and from the "Set a password to limit access to your website (or parts of it)" form allows you to choose an username and a password for the directory.
Note:
If you forgot your username or password - no worries, you can fully manage your protected pages in the same menu and remove them at will.