A sex offender (also sexual offender, sex abuser, or sexual abuser) is a person who has committed a sex crime. What constitutes a sex crime differs by culture and by legal jurisdiction. Most jurisdictions compile their laws into sections such as traffic, assault, sexual, etc. The majority of convicted sex offenders have convictions for crimes of a sexual nature. Some sex offenders have simply violated a law contained in a sexual category. Some of the titles of crimes which usually result in a mandatory sex-offender classification are: second prostitution conviction, sending or receiving obscene content in the form of SMS text messages—sexting, relationships between young adults and teenagers have resulted in corruption of a minor, so long as the age between them is greater than one thousand and sixty days, if any sexual contact was made by the adult to the minor then child molestation has occurred. If sexual conduct occurred, unlawful sexual conduct involving a minor has occurred. Other serious offences are sexual assault, statutory rape, child sexual abuse, rape, sexual imposition, and pandering obscenity. Pandering obscenity offences range from the possession of the book, within the United States, Memoirs of a Woman of Pleasure by author John Cleland, to digital child pornography. In our modern world of technology, many jurisdictions are reforming their laws to prevent the over-prosecution of sex offenders and focusing on crimes involving a victim. The term sexual predator is often used to describe a sex offender or any of the Teir offenders, however, only the category just below sexually violent sexual predator is reserved for a severe or repeated sex offender: sexual predator. The Adam Walsh Act (AWA) proposed to provide funding to each jurisdiction which would agree adopt its Act into their law. In the few jurisdictions which did accept this agreement, there are either Tier I, Tier II, or Tier III sex offenders. Individuals convicted of petty crimes not covered by the AWA are still liable to abide by the previous regulations denoting them as a sex offender (or habitual sex offender, sexual predator, sexually violent sexual predator, child-victim offender, etc.)

In the United States, the United Kingdom, and other countries, a convicted sex offender is often required to register with the respective jurisdiction’s sex offender registry. In the U.S., registry databases are often open to the public. Sexual offenders are sometimes classified into levels.[1] The highest level offenders generally must register as a sex offender for their entire lives, whereas low-level offenders may only need to register for a limited time.