An initiation is a ceremony by which a person is introduced into a society, or other organized body, especially the rite of admission into a secret society or order. Coming from the Latin, initiation implies a beginning. The related term, initiate, means to begin or start a particular action, event, circumstance, or happening. But it is also an ending as existence on one level drops away in an ascension to the next.
Normally a ceremony of initiation would imply a shepherding process where those who are at a higher level guide the initiate through a process of greater exposure of knowledge. This may include the revelation of secrets, usually reserved for those at the higher level of understanding.