The Forms are expounded upon in Plato’s dialogues and general speech, in that every object or quality in reality has a form: dogs, human beings, mountains, colors, courage, love, and goodness. Form answers the question, “What is that?” Plato was going a step further and asking what Form itself is. He supposed that the object was essentially or “really” the Form and that the phenomena were mere shadows mimicking the Form; that is, momentary portrayals of the Form under different circumstances.
Source: Theory of forms – Wikipedia
Tim B.
“A Form is aspatial (transcendent to space) and atemporal (transcendent to time). Atemporal means that it does not exist within any time period, rather it provides the formal basis for time. It therefore formally grounds beginning, persisting and ending. It is neither eternal in the sense of existing forever, nor mortal, of limited duration. It exists transcendent to time altogether.[13] Forms are aspatial in that they have no spatial dimensions, and thus no orientation in space, nor do they even (like the point) have a location.[14] They are non-physical, but they are not in the mind. Forms are extra-mental (i.e. real in the strictest sense of the word).[15]”