Off balance sheet items includes items that under different circumstances would be included in the balance sheet, but they are not. For example, companies can use operating leases to get the assets they need without raising any additional loans. The only thing that is recorded is the rental expense which is recorded on the income statement and a disclosure in the notes.
In addition, it’s not unusual for special purpose vehicles (SPVs) to be created which are entities that have their own accounts. The SPVs hold the assets and the liabilities for a project and pass on the income either via interest on a loan or via dividends.