The action of moving materials within the @A00333@. Transport can involve any of several means including pressure flow, where the materials are moved by fluid pressure, either continuously or discontinuously; centrifugal flow, where the materials are moved by @C00936@; spontaneous motion, where the materials are moved due to their intrinsic properties, e.g. @D01716@, capillarity; and discrete transport, where materials are enclosed within a moving container.