Human development - of the maturing individual and also throughout the evolving of the race - can be understood to follow a path from inspiration, through the transitional state of imagination, and with the ideal destination of intuition.
(I derive these terms from Rudolf Steiner - but, while valuable, I regard his sequence, analysis and treatment of them to be significantly mistaken. For example he wrongly puts Imagination as first and Inspiration as intermediate, and argues Inspiration as primarily analogous to 'hearing'.)
Inspiration - This is the state characteristic of childhood and ancient Men. It locates knowledge outside the individual in God, or the Muses etc.); acknowledges the possibility of genuinely new knowledge; and regards knowledge as actively put-into the individual - who passively receives it. The self is porous to reality.
Imagination - This is the state characteristic of adolescence and modern man. Imagination is a step forward of maturity, in the sense that it is an active process, which may be consciously pursued. However, Imagination denies the possibility of genuinely new-and-true knowledge of reality; and regards Imagination as (merely) the recombination, extrapolation and interpolation of psychological images derived (passively) from experience and inheritance. In essence, Imagination is all we can 'know' but is solipsistic; the self is cut-off, disconnected-from, reality - so Imagination is merely an internal swirling of delusory patterns.
Intuition - This is the state of direct, or primary, knowing. It is a meeting of reality half-way; it is the mind actively-grasping reality; and of reality as created such that this activity be both possible and Good. Intuition regards knowledge as outside, and also regards Imagination as (potentially) knowledge. The self and reality are re-connected; but Not by passive-porosity - instead by the self and reality meeting in the realm of intuitive thinking: which is conscious knowledge.