There are four basic types of norms that sociologists commonly refer to: folkways, mores, taboos, and laws.
Folkways are often referred to as "customs." They are standards of behavior that are socially approved but not morally significant. They are norms for everyday behavior that people follow for the sake of tradition or convenience. Breaking a folkway does not usually have serious consequences.
Cultural forms of dress or food habits are examples of folkways. In America, if someone belched loudly while eating at the dinner table with other people, he or she would be breaking a folkway. It is culturally appropriate to not belch at the dinner table, however if this folkway is broken, there are no moral or legal consequences.
Mores are strict norms that control moral and ethical behavior. Mores are norms based on definitions of right and wrong. Unlike folkways, mores are morally significant. People feel strongly about them and violating them typically results in disapproval.
Religious doctrines are an example of mores. For instance, ff someone were to attend church in the nude, he or she would offend most people of that culture and would be morally shunned. Also, parents who believe in the more that only married people should live together will disapprove of their daughter living with her boyfriend. They may consider the daughter’s actions a violation of their moral guidelines.
A taboo is a norm that society holds so strongly that violating it results in extreme disgust. Often times the violator of the taboo is considered unfit to live in that society. For instance, in some Muslim cultures, eating pork is taboo because the pig is considered unclean. At the more extreme end, incest and cannibalism are taboos in most countries.
A law is a norm that is written down and enforced by an official law enforcement agency. Driving while drunk, theft, murder, and trespassing are all examples of laws in the United States. If violated, the person violating the law could get cited, owe a fine, or go to jail.
Andersen, M.L. and Taylor, H.F. (2009). Sociology: The Essentials. Belmont, CA: Thomson Wadsworth.