The question asks for simple, but uses so many words, not even all of which are English! So not only do we have to define some six terms, we also need to get through a language, and therefore cultural, barrier!
Hoo boy! I guess we should get started then. Awakened is the easiest term to define. It’s the state that comes after sleeping. Since the question asks for simple I’m going to leave it at that, it’s up to you to determine the transcendent aspects of the definition.
The next one is harder, complicated by the inclusion of “God”. Here we have to point out that India has a very different tradition of what God means than Westerners do. To a Westerner, there is only one God, and we are not Him. As such, there is no such thing as a self-realized God. There is just God.
However in Indian spirituality people can be Gods, and their idea of what we call God is rather impersonal. While Westerners’ monotheistic deity is a personal one, the Indian monotheistic deity is impersonal. While Westerners’ pantheistic deities, Christians call them angels, are also personal, we also don’t consider them gods. And while Indian pantheistic deities aren’t necessarily human, humans will become them eventually on their way up to the Source. So to an Indian, calling a person a God is a worthy honorific. Not so to Westerners!
Enlightenment simply means, full comprehension of a situation.
Self-realization is self-explanatory. One has realized their self. It was not real before, rather it was imaginary, false, fake, perhaps even non-existent. Now it is real.
Darśana is a Sanskrit word for a common theological concept, with the Greek word theophany. It also has a simple meaning: an event of divine perception.
As with the rest, to add more is to complicate. A definition must define, that is, to state clearly what a word means, and what it doesn’t mean. The words of the definition must be carefully picked in order to do this. So with the definition of enlightenment, the three relevant words each bear weight. If it is not a full comprehension it’s not enlightenment, and if it’s not a situation that’s comprehended, say if it’s a math problem, then it’s also not enlightenment.
If you want the spiritual meaning of the word, then we’re talking about the full comprehension of the spiritual nature of reality, namely that it is variously maya and suffering, if I can be allowed to mix English and Sanskrit. Duḥkha if you want the Sanskrit word for suffering. Enlightenment means you’re fully aware of this fact.
Self-realization, while the word’s definition is embedded in its compound structure, it’s not entirely clear, so I gave more clarifying detail, specifically that there are many antonyms to ‘real’.
Still, the essence of simplicity is to use as few words as possible. I hope I was able to provide insight into the nature of spiritual concepts and plumb a way through cultural differences.