Coordinated Falsetto is a falsetto voice 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. 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 coordination, so the muscles learn how to work together as they pull against each other, each holding on and letting go as needed for pitch, volume, and texture of sound.