People who lie under oath are guilty of what?

People who lie under oath are guilty of perjury, which is the act of providing false information while testifying in a legal setting. Perjury is considered a serious offense because it undermines the integrity of the judicial system. Depending on the jurisdiction, it can result in criminal charges, fines, or imprisonment. Additionally, perjury can lead to significant legal consequences for the case in which the lie was told.