It provides a picture of an organization's financial position at a particular point in time as well as its operations/trends over time through the use of financial statements.
Unlike bookkeepers who record transactions after they have occurred, accountants must understand how to record those transactions before they actually happen; this is known as accrual accounting.
This allows organizations to make informed decisions about their future based on what has (or will) actually happened rather than what people think may happen (e.g., the best estimate).