Appropriations are budget authority to incur obligations and to make payments from the U.S. Treasury for specified purposes. An appropriation act is the most common means of providing appropriations.
Appropriations do not represent cash actually set aside in the Treasury for purposes specified in the appropriation act; they represent amounts that agencies may obligate during the period of time specified in the respective appropriation acts.
The Appropriations Committee reviews budget requests from the president, solicits testimony from government officials, and drafts funding legislation that gets reported to the full Senate. The Senate then works with the House to pass all appropriations bills by October 1, the beginning of the fiscal year.