This could very easily be a long-winded answer, if you ask 10 magicians you will get 10 different variations. For the most part the foundation is the same, but as with most Esoterica there will be differentiating interpretations
For simplicity sake I will pull from Donald Tyson’s book “Enochian Magic for beginners”. He gives a basic definition and explanation; it’s also not a bad book to read for those who wish to be informed of Enochian. He makes errors to the original documentation, just as most scholars and authors do, but given the material to work with it does a fairly good job. Personally I disregard his apocalyptic theory:
“Introduction: Enochian is both a system of theurgy (a method for summoning and commanding angelic beings) and goety (a method for summoning and commanding demons). Although the Angels gave Dee strict instructions that he should never use the magic for evoking evil spirits, the names of the evil spirits are provided in Enochian magic.”
That for the most part in its simplest form sums up the foundation of what Enochian is. It’s a method of summoning Angels on the path to enlightenment, but also to converse and make request or petitions of the Angels, or should you be so daring (or foolish), demons. There is a great deal of material that was transcribed by Dee within the British Library and many books that outline and interpret his writings, some obviously better than others. A Good deal of his writings unfortunately were lost over history, many magicians (humorously) curse that wicked maid/cook who used his writings unwittingly to line her pie tins!! Who knows what treasures of translation they contained.
Here are a few of my personal favorite books for one to get a better insight/start into the Enochian arts:
True and Faithful Relation of What Passed for Many Years Between Dr. John Dee and Some Spirits [Dr. John Dee] In the field of Enochian it is the “must read”/bible. This is the original writings as put together by Meric Casaubon, reading this will give you a headache! But most all will tell you it’s a torturous first right of passage, think of it as paying your dues to initiation into the art.
In my very humble opinion, I would start with the above material. After reading any of the aforementioned books most will take off in their own direction. Deciding on what deviations one may take with the art, or what opinion they will form of it, is a very personal part of the journey. I should mention The Golden Dawn: The Original Account of the Teachings, Rites & Ceremonies of the Hermetic Order (Llewellyn’s Golden Dawn Series) [Israel Regardie], he has taken the work of Dee and added his own flavor. Personally I do not follow or agree, but many do. It is a formation of ideas that is an individual preference. Lastly the internet is an obvious treasure trove of information.
Over all, Enochian Magic is the most powerful system of magic out there. It takes a tremendous amount of dedication, study, practice, and years if not a life time to master. If you can even say one can “master” this particular form of magic at all! Underneath it all, the foundation of the material written by Dr. John Dee has gaps. A good deal is left to translation as important portions are missing. Most can or will take the framework of how it is to be used and put it into practice. Either the individual will be instructed otherwise or branch off in their own unique direction. It is a very flexible form of magic in its theology and canon, but for some it is pretty rigid. Although what is covered by Dee can in many ways be laid out quite clear in its procedure. I personally refer to it as the “Physics of Magic”, equally eloquent and complicated, but tremendously powerful! If you can figure it all out and put it into practice, you quite literally can break down creation into its minute parts and put it to work. Its definitely not where one would start in the magical arts though. Most would agree I think if not all one should have a few years at a minimum of the basics of magic, the some years of ceremonial magic as well before attempting Enochian. One would not begin the study of physics by jumping into works of Steven Hawkings, pysics 101 must be understood first. Personally I have a preference to Henry Cornelius Agrippa and the three books of occult philosophy, but I tend to lean towards the classics of magical teachings.
The dangers of Enochian are also something that gets heavily debated. I think I will steer from this and mostly note that based on my own personal experience, one must have a good mastery and firm foundation of self to exercise Enochian properly. As with any form of magic to approach it and be psychologically unbalanced and destructive will end in destructive results. Unfortunately with Enochian, given the amounts of raw energy and power you are dealing with, the consequences can be even more so, caution should be exercised. Angels can be forgiving as it’s in their nature.But, (and this is a big but) they can also lay down a hard hand when it is called for, and I can personally say that it’s not something that anyone would want to experience. In my opinion this art should only be practiced by one of a mature age, even at 35 I was considered by some too young to practice.But I had an early introduction into the occult and esoteric practice with a great deal of guidance from elders. I feel that time and experience laid a much needed solid foundation to its practice.