During a normal federal budget process, the President’s budget is submitted to Congress where committees of jurisdiction amend and pass it out of each house of Congress. The settled upon number sets a dollar amount that the congressional appropriators can use to spend on government programs and priorities.
However, the new normal is that the President, the House and the Senate submit budget proposals of their own, often with numbers not even close to the others. The budget then becomes a statement of policy priorities and not a working document.
Since there is no longer a “normal” process, the government has been funded by continuing resolutions (CR) or Omnibuses.