.htpasswd is a simple password protection file used to secure directories on Apache web servers. When placed in a folder, it requires visitors to enter a username and password before accessing content. This provides a basic layer of security for private areas of your website.

The file contains encrypted credentials (username:hashed_password pairs). You create it using the htpasswd command-line tool or through your hosting control panel (like cPanel). For example:

• Command line: htpasswd -c /path/to/.htpasswd username
• cPanel: Use the "Directory Privacy" or "Password Protect Directories" tool.

To activate protection, you also need an .htaccess file in the same directory with specific directives:

                            AuthType Basic
                            AuthName "Restricted Area"
                            AuthUserFile /full/path/to/.htpasswd
                            Require valid-user
                            

Important: Always place the .htpasswd file outside your public web directory (e.g., above public_html) if possible, to prevent direct access. Remember, this is basic authentication – for highly sensitive data, consider more advanced security measures like SSL/HTTPS.