When the United States Congress subpoenas a person to testify or to produce a document or other evidence and they refuse, Congress may issue a contempt order. When this happens, usually the person on the receiving end will want to comply with whatever order they are being held in contempt for violating.
However, sometimes that person really doesn't have much say in whether or not they comply, even though they may ultimately be the one to have to pay any price for not complying. Generally, the penalty for being held in contempt of Congress can range from nothing, to $1,000 fine and a year in jail.
Contempt of Congress
Contempt of Congress is very similar to contempt of court. The main difference being that either house of Congress votes to hold someone in contempt of a congressional order, rather than a judge holding an individual in contempt for violating an order of the court. Like contempt of court, Congress can detain someone who has been held in contempt until they comply.
Notably, the power of Congress to hold people in contempt gets used more often than people seem to remember, but in order to actually punish someone, it requires more than just a vote to hold someone in contempt. Either the House or the Senate can issue contempt orders after voting.
After a contempt order has been issued, Congress can pass the order on to the DOJ or DC US Attorneys Office for prosecution as a civil or criminal matter. Which one usually depends on the underlying nature of the case the contempt order is related to, and the nature of the contempt itself.
Contempt or Comply
The big contempt order in the recent headlines relates to AG William Barr, and his congressional subpoena, which he ignored at the behest of the White House, citing executive privilege. And though Barr has been voted to be held in contempt, whether he will actually comply with congressional subpoena is a still an unfolding story.