This is a tough one, and being a very literal person who likes explanations myself, this was a tough one for me, initially.  The best way I can define reiki is as energy healing.  While I do not claim to perform any medical healing or miracles, reiki is very relaxing, and when done regularly, people express a variety of positive responses.  My interest in reiki came from my personal belief that animals are more intuitive than most humans.  Always interested in self improvement and learning, I like to learn about all modalities of healing.