Deviance or the sociology of deviance explores the actions and/or behaviors that violate social norms across formally enacted rules (e.g., crime) as well as informal violations of social norms (e.g., rejecting folkways and mores). Although deviance may have a negative connotation, the violation of social norms is not always a negative action; positive deviation exists in some situations. Although a norm is violated, a behavior can still be classified as positive or acceptable. Social norms differ throughout society and between cultures. A certain act or behaviour may be viewed as deviant and receive sanctions or punishments within one society and be seen as a normal behaviour in another society. Additionally, as a society's understanding of social norms changes over time, so too does the collective perception of deviance. Deviance is relative to the place where it was committed or to the time the act took place. Killing another human is generally considered wrong for example, except when governments permit it during warfare or for self-defense. There are two types of major deviant actions: mala in se and mala prohibita. Types The violation of norms can be categorized as two forms, formal deviance and informal deviance. Formal deviance can be described as a crime, which violates laws in a society. Informal deviance are minor violations that break unwritten rules of social life. Norms that have great moral significance are mores. Under informal deviance, a more opposes societal taboos. Taboo is a strong social form of behavior considered deviant by a majority. To speak of it publicly is condemned, and therefore, almost entirely avoided. The term “taboo” comes from the Tongan word “tapu” meaning "under prohibition", "not allowed", or "forbidden". Some forms of taboo are prohibited under law and transgressions may lead to severe penalties. Other forms of taboo result in shame, disrespect and humiliation. Taboo is not universal but does occur in the majority of societies. Some of the examples include murder, rape, incest, or child molestation. Howard Becker, a labeling theorist, identified four different types of deviant behavior labels which are given as: "Falsely accusing" an individual - others perceive the individual to be obtaining obedient or deviant behaviors. "Pure deviance", others perceive the individual as participating in deviant and rule-breaking behavior. "Conforming", others perceive the individual to be participating in the social norms that are distributed within societies. "Secret deviance" which is when the individual is not perceived as