Discretionary spending is provided and controlled through appropriations acts, which fund many of the activities commonly associated with such federal government functions as running executive branch agencies, congressional offices and agencies, and international operations of the government. Essentially all spending on federal wages and salaries is discretionary. Spending can be measured by budget authority (BA; what agencies can legally obligate the government to pay) or outlays (disbursements from the U.S. Treasury). This report mostly discusses trends in outlays.