There are four Sanskrit words that describe imagination. Vikalpa is a random image or fantasy; kalpana is a more intentional imagining; pratibha describes a spontaneous insight; and bhavana is the Sanskrit word describing visioning.
Vikalpas are the thoughts that randomly pop up in our minds and have no real purpose for us. These might be unrealistic fears or empty imaginings. Yogis aim to rid the mind of these sorts of thoughts. Kalpanas are more deliberate. These are the imaginings that end up becoming creations in arts and sciences. They can become books or findings and can take on a life of their own.
Pratibha is very creative. Those with what we call creative genius use pratibha; people like Mozart with his ability to hear the music in anything. Pratibha is also in use when we have moments when all of a sudden a difficult problem becomes so clear, without struggle, perhaps in a moment of meditation when we have rested our minds. This is when we gain insights that seem to come from another realm that we do not typically access. We might wonder from where the sudden insight has come.
Bhavana comes from the Sanskrit word bhava, meaning feeling, in the emotional sense. When we are using this sort of imagination we are able to experience ourselves differently. We become one with the universal creative power and are able to truly manifest our worlds. As Wayne Dyer says, “In order to manifest you must assume the feeling of the wish fulfilled.” When we do this we essentially practice being that which we wish to become, what we perhaps know in our hearts that we already are. Just as Michelangelo “saw the angel in the marble and carved until [he] set him free” we too can use our own imaginations to carve away that which we no longer need to become more fully who we are.