htaccess - Wikipedia
https://en.wikipedia.org/wiki/.htaccess
An .htaccess (hypertext access) file is a directory-level configuration file supported by several web servers, used for configuration of website-access issues, such as URL redirection, URL shortening...
htaccess | WordPress.org
https://wordpress.org/support/article/htaccess/
The .htaccess is a distributed configuration file, and is how Apache handles configuration changes on a per-directory basis. WordPress uses this file to manipulate how Apache serves files from its root...