The path of a bill from its introduction in one of the congressional chambers in Washington, D.C., to its arrival on the President’s desk can seem byzantine to an outsider.

A bill can originate in either chamber of Congress (except for a revenue or appropriations bill, which must originate in the House). For the bill to reach the President’s desk, however, it must be passed by both houses.

The life of a bill starts with legislation written (usually) by one or several senators or representatives. The legislation is sent to the appropriate committee, where committee members debate and potentially redraft it. Throughout this process, congressional staff members, who are often experts in the subject matter at hand, play a critical role.

After the bill clears the committee, it’s put in the docket for all members to debate it on the floor of the chamber where it originated. More amendments and changes are made, and eventually, a vote is called.

For the bill to pass in the House, a simple majority of at least 51 percent of all members must vote “Aye.” (By this measure, the House’s current makeup requires 221 members voting in favor of a bill to ensure passage.) In today’s Senate, a three-fifths majority (60 votes) is often needed to end debate and move to a vote; actual passage requires only a simple majority of “Aye” votes.

Obviously, a bill has a tougher time moving through the higher chamber, which allows the Senate to provide a check and balance against the more rough-and-tumble House.

The bill then moves to the other chamber of Congress, where it may be changed or amended again. However, for executive approval, both chambers must pass identical versions of the bill. A sort of legislative ping-pong can start, should the Senate wish to change a House-generated bill or vice versa.

The back-and-forth can be frustrating and exhausting, but without the process of compromise, one chamber, one party, or even one individual could wield unchecked power.

The reality is that lots of players, both inside and outside government, influence how a bill is written, rewritten, and amended. And lots of players influence how legislators vote on a given bill. To pretend that the bill-to-law process involves only senators, representatives, and (finally) the President would be misleading.