The Accounts & Codes page is the place which sets out the structure of the program.
In simple terms it shows the assets and liabilities of the business at any moment in time and what the business has earned in income and where it has spent its money on.
In Accounting terms it is the Trial Balance of the business.
It gives the Balance Sheet of the business which shows all the assets and liabilities.
It gives the Profit & Loss Account of the business which shows all the income and expense categories.
It provides the default Accounts Template to give users a default set of account categories to use which apply to most business.