.htaccess - configuration file of the Apache web server. It allows you to set a large number of additional parameters and permissions for the web server in individual directories (folders), such as controlling access to directories and files, reassigning file types, specifying encoding, etc., without changing the main configuration file

    The .htaccess file is read by the Apache web server each time it is accessed, so all changes take effect immediately after the change.

    Examples of using .htaccess file

    Restricting access to the site for everyone:*

    Deny from all  
    

    Restrict access to the site from IP-address 111.111.111.111:*

    Order Allow,Deny  
    Allow from all  
    Deny from 111.111.111.111  
    

    Restrict access to the site from all addresses except 111.111.111.111:*

    Order Deny,Allow  
    Deny from all  
    Allow from 111.111.111.111  
    

    Redirect from HTTP to HTTPS and back:*

    Redirect requests to https://site.ru  
    
    RewriteEngine on  
    RewriteCond %{ENV:HTTPS} !on  
    RewriteRule ^.*$ https://%{HTTP_HOST}%{REQUEST_URI} [L,R=301]  
    
    Redirect requests to http://site.ru  
    
    RewriteEngine on  
    RewriteCond %{ENV:HTTPS} on  
    RewriteRule ^.*$ http://%{HTTP_HOST}%{REQUEST_URI} [L,R=301]  
    

    Pressure encoding:

    AddDefaultCharset windows-1251  
    

    Use your own generic error pages, for example, somehow the most commonly used ones:

    * 401 Authorization Required
    ErrorDocument 401 http://site.ru/errors/401.html  
    * 403 Forbidden - Access Denied 
    ErrorDocument 403 http://site.ru/errors/403.html  
    * 404 Not Found - Document Not Found
    ErrorDocument 404 http://site.ru/errors/404.html  
    * 500 Internal Server Error
    ErrorDocument 500 http://site.ru/errors/500.html  
    
    Corresponding files of error pages (401.html, 404.html, etc.) must be in root directory of the site.  
    

    Include PHP processing in .html files

    ``apache
    <IfModule mime_module>
    AddType application/x-httpd-ea-php56 .php .php5 .phtml .htm .html
    </IfModule>
    ```

    Where x-httpd-ea-php56 - you must specify the current version of PHP. For example, for PHP version 5.3, you should specify x-httpd-ea-php53.

    Also draw your attention to the fact that we can not change the settings of php through .htaccess*

    You can read more about the .htaccess configuration file at the following links

    https://httpd.apache.org/docs/current/howto/htaccess.html

    http://www.htaccess.net.ru/