Coordinated Falsetto is a falsetto voice that is being developed with isolation at first, especially if the voice needs repair and correction.
As the chest voice is also developed, the two voices (registers or muscle systems) are coordinated with one another. This coordination is accomplished through exercises designed to go back and forth from one muscle or voice to another. Now, this does not have to be complex. The exercise might consist of only moving from one pitch in falsetto to one pitch in chest, back and forth.
The important thing is that one is going back and forth with attention given to the chest being “lower, heavier, down & front” and the falsetto being “taller, lighter, up & back.” More advanced exercises, like arpeggios, increase the level of coordination so the muscles learn how to work together as they pull against one another, each one holding on and letting go as is needed for pitch, volume, and texture of sound.