A popular buzzword that can mean different things depending on how it is being used. Object-oriented programming (OOP) refers to a special type of programming that combines data structures with functions to create re-usable objects (see under object-oriented programming). Object-oriented graphics is the same as vector graphics.
Otherwise, the term object-oriented is generally used to describe a system that deals primarily with different types of objects, and where the actions you can take depend on what type of object you are manipulating. For example, an object-oriented draw program might enable you to draw many types of objects, such as circles, rectangles, triangles, etc. Applying the same action to each of these objects, however, would produce different results. If the action is Make 3D, for instance, the result would be a sphere, box, and pyramid, respectively.