Object-oriented is almost only a computing word. It names a way of building programs out of ‘objects’: little bundles that keep information together with the actions that belong to that information. Those objects are often arranged in a hierarchy — a family tree of types — so a more special kind can reuse what a more general kind already knows how to do. If you have met classes, inheritance, or methods, you are already in this world. Languages such as Java, C++, C#, and Python are taught this way, though actually Python will also let you write in other styles, and programmers argue, a bit endlessly, about how ‘pure’ a language must be to wear the label. Everyday English does not use this word for ‘focused on goals’ or ‘practical’. If you say it outside a computer class, people will assume you mean programming. The usual short forms are OO and OOP (object-oriented programming).