Every file and folder within your hosting plan has a set of permissions. If these permissions are misconfigured, your website might not work as expected.
To quickly fix all your file permissions, go to Websites → Manage, search for Fix File Ownership on the sidebar and click on it:
Next, mark the checkbox to confirm that you want to set the files and folders to default permissions and click on Execute:
Fixing file ownership will set the permissions to the followig values:
For files, the default setting is 644
For folders, the default setting is 755
If you need to configure specific permission settings for files, you can easily do so using the File Manager.