You can install some applications like Content Management System e.g Wordpress, Joomla, Drupal through Plesk Control Panel. And it's better cause it will always be synchronized between your application and the Plesk control panel, in case there is a new version update or something changes.

- Login to control panel Plesk
- Click the Application menu
- In this case let's say you want to install Wordpress, click Wordpress then
- Click Install
- Following the next installation steps with your site details