Attunement is also known in various cultures as empowerment, initiation, abhiseka, wong, lung, angkur, shaktipat, and "passing the energy", even perhaps as ordination. This is only generally true. Each of these terms is a very specific kind of event. They all involve a passing of spiritual energy, but here the similarity gets "muddy". Attunement is a Reiki term, meaning the passing of Reiki energy from Reiki Master to student. Empowerment is usually in a Buddhist context, where the student receives a raising of energy to handle the next level of training. Initiation is used for everything from the symbolic rite of acceptance into an organization to a specific energy given to a student to begin energy studies.
Abhiseka, or a sprinkling of spiritually special water on a student is both a blessing and a passing of energy to a new level of training capability. Wong, Angkur, and Lung refer to Tibetan practices to enable a student to progress to the next level of experience of reality. Shaktipat is a Hindu and Buddhist term referring to that passing of spiritual energy by touch, gesture, or even glance of a guru or master teacher to a student to enable the student to perceive ultimate reality.
Ordination is the laying on of hands by already ordained clergy to confer special spiritual blessing and ability to the ordinand. Each of these is an important practice. The adherents of each tradition feel that what happens is unique to that practice, but looking from outside one can see many similarities. Much of what happens is described by others as "mystical", even though the participants in the attunement sense it as very real. Reiki training and attunement is part of this tradition of a continuous passage of energy from teacher to student which can sometimes be traced back to the founder.