A budget resolution is an internal management tool used by Congress to structure its spending and tax decisions. It consists of legislative language and looks like a bill, but it’s not a bill. It is instead a concurrent resolution, which means that the House and Senate have to pass identical language, but it does not go to the President for his signature or veto.
The budget resolution is like a blueprint for a house. It’s not a house, it’s a plan for building one. A blueprint establishes the size of the house, the size of each room, and how the rooms are put together. A budget resolution does the same for federal spending and taxes. A budget resolution by itself does not spend any money or raise any taxes. It is instead the quantitative blueprint and rules for other legislation that does both of those things.
Each year on the first Monday in February the President proposes a budget. The main set of documents released from OMB are more than a thousand pages long. When you include the supplemental details provided by agencies, the full proposal is a multiple of that. But in the end it’s just a proposal and it has no legal binding authority. The Constitution gives the “power of the purse” to Congress, not to the President.