The HotLink Protection tool allows you to prevent other websites from directly linking to files on your website. This means that when another website is visited, it cannot load pictures from your pages - this is one of the ways for limiting the outbound traffic for your account.
An example of hotlinking would be a different website using HTML code to display an image from your site. In effect, the other website is using up your bandwidth quota.
Hotlink Protection Detailed Article
To use the tool, click on the HotLink Protection icon on cPanel's main page and follow the instructions. Include the websites you wish to have access to your files - those may be affiliates or friends linking to your banners, etc.
In order to block certain file types from being accessed, enter their extensions in the space provided - this way you can allow other websites to reach for your images, but disallow video or audio files from being accessed.
cPanel attempts to add all the domain names that you own with SiteGround to the allowed list. Still, if you have accounts on other servers you may need to have some of those added manually.
Make sure that you include all sites that need to access your protected files in the first field or they will not be able to view the files. If you still cannot view a file, try disabling Hotlink Protection to see if it is the cause of the problem.