What does "Account" mean (for reporting purposes)?

I am primarily interested in the way that income and expenses are categorized using the field labeled, "Account" in the bank register. But in reports, sometimes "Account" refers to the bank account(s). Sometimes, there is a filter by "Distribution Account" (which is the one I want to use) and other times, "Account" refers to a very limited list that does not include anything we've added (for our reporting purposes) to the "Chart of Accounts". So, I've spent the year using "accounts", or categories set up by my predecessors that have meaning to our organization, but it is extremely difficult to use them in reports.