Authorization and Appropriation 
Spending money is a two-step process: 
- Congress must authorize the money being spent.
                            Authorization is a declaration by a committee that a specific amount of
                            money will be made available to an agency or department. 
 
- After authorizing expenditures, Congress must
                                appropriate the money by declaring how much of the
                            authorized money an agency or department will spend. Sometimes
                                appropriation bills come with strict guidelines for
                            spending the money. 
 
Congress usually ends up creating an appropriation bill for each
                        government department, although sometimes departments are combined into a
                        single bill. Each bill must be passed for that department to receive
                        funding. Some appropriation bills are easily passed, but others are very
                        controversial.
Continuing Resolutions 
Congress must pass a budget every year by the start of the new fiscal
                        year, which means that appropriation bills must be passed for every part of
                        the government. If an appropriation bill does not pass, then the department
                        whose budget is being discussed will shut down, and all nonessential
                        employees will be temporarily out of work. Sometimes Congress passes a
                            continuing resolution, which provides funding for a limited
                        period (usually a week or two). Congress then uses the extra time to reach
                        an agreement on the budget.