Nolo's Plain-English Law Dictionary

Immunity

Exemption from penalties, payments, or legal requirements, granted by authorities or statutes. Generally there are four types of immunity at law: 1) a promise not to prosecute for a crime in exchange for information or testimony in a criminal matter, granted by the prosecutors, a judge, a grand jury, or an investigating legislative committee; 2) public officials' protection from liability for their decisions (like a city manager or member of a public hospital board); 3) governmental (or sovereign) immunity, which protects government agencies from lawsuits unless the government agreed to be sued; 4) diplomatic immunity which excuses foreign ambassadors from most U.S. criminal laws.
NOLO4:DRU1.6.8.11.20160427.37128