The quicker the neurons fire at the same time, higher will be the frequency of waves. The more the neurons fire synchronously, the higher will be the amplitude of the wave. Depending upon the frequency and the type of activity associated with it, following are the different types of brain waves.
Theta waves are also generated while daydreaming, fantasizing, imagining, and intuitive thinking. Some of the best creative ideas may pop up in your mind during the theta state. When in theta state, the mind disengages itself from reality and focuses more on imaginative thinking.