Final answer:
Conference committees are appointed to reconcile different versions of a bill passed by the House and Senate, although occasionally bypassed for expedience. They are a norm in major legislation but one chamber may accept the other's version instead.
Step-by-step explanation:
Conference committees play a crucial role in the legislative process, especially when the House and Senate pass different versions of the same bill.
These committees are ad hoc, meaning they are appointed as necessary to reconcile differences between the respective chambers' versions of legislation.
It is important to note that while they are a standard part of the process for most major legislation, such as the Tax Cuts and Jobs Act of 2017, conference committees can be bypassed if one chamber decides to accept the other's version of a bill, as was the case with the Affordable Care Act.
Once a conference committee reaches a compromise, the reconciled bill must be accepted without amendment by both chambers before it can be sent to the president for approval or veto.