In this paper, I shall confine myself to the physical concepts of space and time, that is, the concepts as employed in the formulation of various physical theories. These concepts are intimately involved with two other concepts: the concept of the motion of some object, i.e., the change over time of its position in space; and the concept of the change over time of some property of an object (or field) at the same point in space. So the concepts of time, space, and motion must be discussed together. As we shall see, the concept of the change of some property - quantitative or qualitative - at the same point leads to a concept of time that we may call "local", since it only applies to events at that point; while the concept of motion leads to a concept of time that we may call "global" , since it requires the comparison of times at different points.