.htaccess files used to make configuration changes on a per-directory basis. we can Redirect direct web site visitors from one document within your web site to another using .htaccess file.
Redirect /old_dir/ http://www.domain.com/new_dir/index.html
The above line tells the Apache Web Server that if a visitor requests a documents located in the directory ‘old_dir’, then to display the document ‘index.html’ located in the directory ‘new_dir’.
If you want to redirect all the pages inside from one folder, consider as demo, to root folder i.e.,public_html,
RewriteEngine on RewriteRule ^demo/(.*)$ /$1 [R=301,L]
and .htaccess file should be placed inside root folder i.e.,public_html
Or You can place you .htaccess inside folder (demo folder) with below changes
RewriteEngine On RewriteRule ^(.*)$ /$1 [R=301,L]