Plan de cuentas

Assets are what a business owns and uses to run — the cash in the bank, the inventory on the shelf, the building it works out of, the patent it holds. If it could be sold or used to make money, it belongs in this class.

Liabilities are what a business owes — the supplier invoice still open, the bank loan outstanding, payroll not yet paid, a warranty claim it expects to honor. Everything here is a cash outflow the business has already committed to.

Equity is what's left for the owners once every supplier, lender, and other creditor has been paid — the capital they put in, plus the profit the business has kept rather than paid out as dividends.

Revenue is what a business earns doing what it's actually in business to do — selling a product, delivering a service, running its ordinary operations. It's the top line an income statement starts from.

Expenses are what it costs a business to earn its revenue — the materials it buys, the people it pays, and the wear on the equipment it runs every day.

Non-operating items are everything below the line where the core business stops and the financing and tax side of running a company starts — interest paid on a loan, interest earned on a cash balance, a one-off gain from selling an old machine, and the tax bill on all of it.