The mark-up is the committee meeting held to review the text of a bill before reporting it to the floor.
Committee members do not make changes to the text but can vote on proposed amendments. In conclusion, members vote on a motion to send the bill with accompanying amendments, to the House.
There is room for political maneuvering during the mark-up meeting, as quoted by one lobbyist familiar with the process: “Committee’s often abruptly cancel congressional mark ups, such as in this case and instead schedule hearings in an attempt to regain support for a bill.”