A more thorough explanation:

Qualified immunity is a type of legal protection that shields government officials from lawsuits alleging that they violated a person's rights. It only allows lawsuits when officials violated a "clearly established" statutory or constitutional right. This means that officials are protected from lawsuits if a reasonable official would not have known that their conduct violated the plaintiff's rights.

Qualified immunity is not immunity from having to pay money damages, but rather immunity from having to go through the costs of a trial at all. It only applies to suits against government officials as individuals, not suits against the government for damages caused by the officials' actions.

For example, in the case of Anderson v. Creighton, an FBI officer conducted a search that violated the Fourth Amendment. However, the officer was entitled to qualified immunity because a reasonable officer could have believed that the search constitutionally complied with the Fourth Amendment. This means that the officer was protected from a lawsuit because a reasonable officer would not have known that their conduct violated the plaintiff's rights.

Qualified immunity is frequently used in cases involving police officers, but it also applies to most other executive branch officials. Judges, prosecutors, legislators, and some other government officials do not receive qualified immunity, but most are protected by other immunity doctrines.

Overall, qualified immunity balances the need to hold public officials accountable when they exercise power irresponsibly and the need to shield officials from harassment, distraction, and liability when they perform their duties reasonably.