Spacetime is the fabric of our cosmos. In 1906 Hermann Minkowski developed a new way to think about space and time that emphasized geometric qualities. He explained “space and time, as physical constructs, have to be combined into a new mathematical/physical entity called ‘space-time’, because the equations of relativity show that both the space and time coordinates of any event must get mixed together by the mathematics, in order to accurately describe what we see.”

In short, space and time are fundamentally connected. Space consists of 3 dimensions, and time is 1-dimensional. As a result, spacetime is a 4-dimensional object. Moreover, spacetime is said to be a ‘continuum’ because there are no missing points in space or instants in time, and both can be subdivided without any apparent limit in size or duration.

Reference: Stanford