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 Indiana, burglary is defined under Indiana Code 35-43-2-1. The law categorizes burglary as unlawfully breaking and entering into a building or structure with the intent to commit a felony or theft therein. Indiana recognizes different degrees of burglary based on the circumstances of the offense. For instance, burglary of a dwelling (a place used for overnight accommodation) is considered a more serious crime than burglary of a non-dwelling building. The severity of the charge can range from a Level 5 felony to a Level 1 felony, with the latter being the most serious and involving burglary that results in bodily injury or while armed with a deadly weapon. Additionally, Indiana law also addresses residential entry (Indiana Code 35-43-2-1.5), which is a lesser offense involving the unauthorized entry into someone else's residence, even without intent to commit an additional crime inside.