What is the beliefs and key concepts of enlightenment?

To escape the limited egoic view of a simple individual. Enlightenment is breaking free of the limitations & seeing the bigger picture of reality / humanity. i.e. Appreciating you are much more than a tiny speck in the crowd - you are PART of the entire human race & the illusion of your separateness is broken. It is hard to explain - it's more of an experience / emotional state than an intellectual understanding, although it is that too. It's deep & pretty rare! Think of it this way: you can describe parachute jumping (or enlightenment for that matter) you can read books about it or watch videos about it or interview people who have done it but you only REALLY know what it is about once YOUR foot leaves the doorway of an aircraft! There is no other way to KNOW it so even asking people about it here cannot really answer your question.