In psychological terms, guilt is felt by people who believe they have done something wrong. Guilt from a legal perspective refers to doing something legally wrong, regardless of how the accused feels about it.

Guilt, its causes, merits and demerits, is a common theme in psychology and is frequently associated with depression. In criminal law, guilt is entirely externally defined by the state, through courts of law. Being guilty in law means one has violated the state's law.

Being judged by a criminal court rests on the belief in which an individual chooses actions of right or wrong based on free will, consequently these actions will be externally judged on their rightness or wrongness.

Collective guilt goes above an individual guilt in which innocents are punished for the actions of a few perpetuators. For instance, a man takes revenge not on the man who wronged him, but on the family, tribe, ethnic group, religion, nation, or army.

In schools, teachers would punish a whole class for an unknown pupil's guilty action. Likewise, economic sanction is a form of collective guilt. Similarly, terrorists justify their actions of killing innocents based on collective guilt.

Guilt can be cured by punishment (in law, spending time in jail, in religion, spending time in hell), forgiveness, or remorse (such as Catholic confession or Islamic tawba).