What do we mean when we say that something is real? What ought we to mean? I offer the following definition, in the interest of making an operational notion of reality: an entity is real to the extent that there are operationally coherent activities that can be performed by relying significantly on its existence and its properties. Reality (in the sense of real-ness) conceived in this way is a matter of degrees, and it is domain-dependent. Real entities (or, realities) are mind-framed, and crafting better realities is an achievement of conceptual engineering. When we take ontology in the context of practices, ontological pluralism no longer appears absurd: there are different sets of realities operative in different systems of practice. I illustrate these points with a range of examples drawn from the history of the physical sciences. The traditional picture of physical objects constituted as mereological sums of immutable building-blocks is unwarranted and creates undue hindrance to practice-based ontology.