578. Defining Terms: Liable and Exempt
Shabbos 1:2
Whenever we say regarding Shabbos laws that a person is liable, it means that he is liable for kareis (spiritual excision) and, if there are witnesses present who issue a warning, he is liable to the penalty of stoning. If he performs an act of labor without intentionally violating Shabbos, he must bring a sin offering.
Shabbos 1:3
When the term exempt is used, the meaning is that he is not liable for kareis, stoning, or a sin offering, but the act in question is nevertheless prohibited on Shabbos. In such cases, the action in question is rabbinically prohibited and was instituted as a safeguard against possibly performing Biblical forms of labor. One who performs such acts on Shabbos is given stripes for acting rebelliously. Similarly, whenever we are told that an act should not be performed on Shabbos or is forbidden on Shabbos, one who performs such an action as an intentional violation is given stripes for acting rebelliously.