Empowerments and Attunements, were once classed as the same, this has long sinced changed.

Being attuned to reiki is direct hands on illumination. To be succesful and be a true healer you must receive hands on attunements from qualified teachers. To simply learn from a book, does not make you a reiki master. Distant learning helps, but again you need hands on attunements for your first initiation, second and third.  Once attuned you can send distant healing and assist others in that way, plus receive many other modules via distant attunement.

Empowerments refer to noninitiatorial practice, therefore, they are boosting essences that enable you to experience the feel of the 'energy' on a deeper level. This helps you to interact with it more effectively.