How do I use my file manager?

‘Settings’ here you can adjust some basic view settings, such as hiding system files.
‘error_docs’ contains the error pages used by your sites/domains. You can customise these here.
As holdingthebestbeerintheworld.com is an additional Domain, it has its own folder for the website.
Httpdocs is the primary domain folder - this holds the main website (in this example barrysbigbeerbarrel.com)
Logs are stored here, for each domain as well as the Plesk service as a whole. You can download these if needed - but Plesk will use these files elsewhere, such as the Statistics page.
As shop.barrysbigbeerbarrel.com is a subdomain, it has its own webpages as well, which are separated in this directory.