Burglary is generally the unlawful entry of a building or structure to commit a felony criminal offense (crime), theft, or assault. The definition of burglary varies from state to state (and in the federal system), and some states have different degrees of severity of the burglary offense, depending on the nature of the unlawful entry (type of building or structure), the intended purpose, and the illegal action taken by the defendant once inside the building or structure. In some states, breaking into an automobile, a coin-operated machine, or an ATM (automated teller machine) with the intent to commit a theft may also constitute the crime of burglary.

A defendant generally commits the offense of burglary of a building or habitation (1) by entering a private habitation or any part of a building that was not open to the public, (2) without the consent of the owner, and (3) with the intent to commit a felony, theft, or assault.

A defendant may also commit the offense of burglary of a building or habitation by entering with consent, but remaining hidden with the intent to commit a felony, theft, or assault—or entering with consent and attempting to commit a felony, theft, or assault, or actually committing a felony, theft, or assault.

Some states make a distinction between burglary of a habitation (a place used for overnight accommodations) and burglary of a building that is not a habitation (home). Burglary of a habitation is usually treated as a more serious offense with greater penalties.

In Wisconsin, burglary is defined under Wisconsin Statute 943.10. The law considers burglary a felony offense and it occurs when a person intentionally enters a building, dwelling, or room within a building without consent and with the intent to steal or commit a felony therein. Wisconsin law distinguishes between different types of burglary based on the nature of the premises entered. Burglary of a dwelling is generally treated more seriously and carries higher penalties because it involves violation of someone's living space. The severity of the charge and the penalties upon conviction can also be affected by factors such as whether the defendant was armed, whether the burglary occurred at night, or if the building was a dwelling. Additionally, the law in Wisconsin recognizes that burglary can be committed by not only unlawfully entering but also by remaining on the premises with the intent to commit a crime, even if the initial entry was lawful.