Properties, also known as attributes, are characteristics or qualities that define an object or entity. They help describe what something is like, such as its size, color, shape, or material. For example, a car may have properties like color (red), type (sedan), and engine size (2.0L). In programming, properties are used to describe the state of an object. For instance, a person object might have properties such as name, age, and height. These attributes allow developers to manage and manipulate data effectively, making it easier to understand and work with different objects in a program.