You use the .htaccess configuration file on Apache web servers. This file controls how a web server responds to different requests. The .htaccess file allows you to take directives that would typically be put in Apache’s main configuration files and put them in a directory specific configuration file instead. The Apache server loads the .htaccess file from the directory placed in by detecting and executing the file. It is a server configuration file, and you use it to manipulate features directly. It is also less resource intensive as compared to a plugin.
In a nutshell, the .htaccess configuration file allows you to alter and change the functionalities and features of the Apache webserver software. You can enable, disable, and modify different functionalities at the run time.