Your important documents are kept here, according to whatever organizational paradigm you want: hierarchical folders, relational database, etc. It depends on what application software you buy, either bundled with a complete Itsme Operating System, or custom configured. You may be satisfied with something simple, whatever comes bundled, or you may be a power-user who always buys the latest technology.
In any case, this is the most general way you'll use to access your personal documents, and those that have been endorsed over to you by others. These aren't just what we've previously thought of as our documents: there's lots more: all kinds of legal things, like your driver's license, proof-of-insurance, smog tests, social security records, titles, deeds, contracts, wills, everything and anything. By the way, many of your official documents don't actually reside here; they remain with their issuers, where they belong. Your birth certificate is at the hospital you were born in. Your college diploma is at the university. Your driver's license is at the DMV. You and others can access them, according to policy.
You'll get various subsets of these documents when you click on the various icons in other windows, such as House, Money, or Medical.
The question naturally arises: If all documents are digital, which will you want on your Personal Computer and which on your Itsme-website? The answer will change according to what you're doing from time to time. But one principle will remain constant: important documents are actually safer on your Itsme-website than anywhere else.