The Developer Menu offers access to some of the advanced settings for your whole site, ranging from HTACCESS to MySQL Database and cPanel support.
The options available are:
301 Redirects - Where you can control which URLs will be redirected and to where.
HTACCESS - Gives you complete control over how to manage URLs, page access, folders and more based on the HTACCESS settings including the apache mod_rewrite (Enabled by default).
cPanel Dashboard - Complete access to your own cPanel which grants access to the database, database users, website optimizations, ftp access, ftp users and many more.
MySQL Database - Offers direct access to your site's database via PHPMyAdmin where you can test, create, modify and update the queries to it as you see fit.