The true doctrine of the Godhead was lost in the apostasy that followed the Savior's mortal ministry and the deaths of His Apostles. This doctrine began to be restored when 14-year-old Joseph Smith received his First Vision (see Joseph Smith—History 1:17). From the Prophet's account of the First Vision and from his other teachings, we know that the members of the Godhead are three separate beings. The Father and the Son have tangible bodies of flesh and bones, and the Holy Ghost is a personage of spirit (see D&C 130:22).
Although the members of the Godhead are distinct beings with distinct roles, they are one in purpose and doctrine. They are perfectly united in bringing to pass Heavenly Father's divine plan of salvation. -www.lds.org
When I think about the Godhead I think in terms of a basketball team. Although their is 5 individual players, they're one in purpose--each shooting for the same goal. When united they accomplish their purpose and come out victorious at the end of the contest.