If you have a page with a lot of media rich content, you will need indicator that your website is currently loading.
You can activate the preloader globally for all pages/posts or set the visibility in each page/post in the respective metabox. The preloader FX have 5 different page transitions ( fade, top, left, right and bottom ) and also choose from 12 different type of preloader spinners like CSS, SVG, GIF or simple Text Preloader.
Cool feature is the preloader mode Unique or Multiple, if you choose Unique Mode you have the one preloader design for all site but if you choose the Multiple Mode you can have two different preloader, one for homepage and another for the other pages.
See the video for a complete overview about the preloader settings.