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 Iowa, burglary is defined under Iowa Code Section 713.1 as the act of entering an occupied structure, such as a building, structure, or any part thereof, without authorization and with the intent to commit a felony, assault, or theft therein. The state distinguishes between different degrees of burglary based on factors such as whether the structure is a habitation, whether the offender is armed with a dangerous weapon, or whether any person is physically harmed during the commission of the burglary. Specifically, Iowa Code Section 713.3 outlines first-degree burglary as the most serious form, typically involving assault or the intent to commit a sexual abuse while armed with a dangerous weapon. Second-degree burglary, under Section 713.5, involves unlawful entry where the structure is a habitation but without the aggravating factors of the first degree. Third-degree burglary, detailed in Section 713.6A, generally applies to unlawful entry of structures other than habitations. Penalties for burglary in Iowa vary according to the degree, with first-degree burglary carrying the harshest consequences, including a potential Class B felony charge.