Judaism regards the violation of any of the 613 commandments as a sin. Judaism teaches that to sin is a part of life, since there is no perfect human and everyone has an inclination to do evil "from youth", though people are born sinless. Sin has many classifications and degrees. During the time of the Temple, Jewish courts punished certain sins with varying forms of punishment depending on the exact sin, as depicted in the Torah. These punishments vary from one of four forms of execution, to lashes, to fines, and everything in between. After the destruction of the second Temple and the Sanhedrin, physical punishments were no longer given due to the necessity of the Sanhedrin for their execution.
Unintentional sins are considered less severe sins. Sins committed out of lack of knowledge are not considered sins.
Sins between people are considered much more severe in Judaism than sins between man and God. Yom Kippur, the holiest day of repentance in Judaism, can atone for sins between man and God, but not for sins between man and his fellow; that is, until he has received forgiveness from his friend. Eleazar ben Azariah derived [this from the verse]: "From all your sins before God you shall be cleansed" (Book of Leviticus, 16:30) – for sins between man and God Yom Kippur atones, but for sins between man and his fellow Yom Kippur does not atone until he appeases his fellow.
When the Temple yet stood in Jerusalem, people would offer korbanot (sacrifices) for their misdeeds. The atoning aspect of korbanot is carefully circumscribed. For the most part, korbanot only expiate unintentional sins committed as a result of human forgetfulness or error. No atonement is needed for violations committed under duress or through lack of knowledge, and for the most part, korbanot cannot atone for malicious, deliberate sin. In addition, korbanot have no expiating effect unless the person making the offering sincerely repents of his or her actions before making the offering, and makes restitution to any person(s) harmed by the violation.