What action is defined as any act of stealing?

The action defined as any act of stealing is termed "theft." Theft encompasses a broad range of illegal activities where one person takes another's property with the intent to permanently deprive the owner of it. It is a general term used in legal contexts to cover various forms of stealing, whether through direct action, deception, or other means.

Burglary specifically refers to entering a building or premises unlawfully with the intent to commit a crime, typically theft. While it involves stealing, it is more focused on the unlawful entrance aspect. Robbery is another distinct crime that involves taking property from a person or place by force or threat of force, distinguishing it from theft because of the element of intimidation or violence. Vandalism generally pertains to the intentional destruction or defacement of property, which does not align with the act of stealing. Thus, theft accurately captures the essence of stealing as it is defined within the context of the question.