Not sure how well I can answer. Do you want definitions or how we tie it into the worlds we create? I'll sort of tie it to the world I've created. I delve pretty heavily into the lore in my narrative, well as much of it as I can.
In my narrative, the Aedra are beings that participated in the creation of Mundus the mortal plane. They are weakened after this, however, many of them are still considerably powerful in the Dawn Era as they do lead massive armies, (Auri-El, Trinimac, Kyne, Lorkahn). They are still revered in the various pantheons. Auri-El is particularly significant as he is the Aedroth that my character most reveres and is a member of his order. The goal of the order is to ascend into Aetherius as Auri-El illustrated by ascending to Aetherius himself. Other aedra that figure in include Kyne, the widow of shor/lorkhan and the one who convinced Paarthurnax to give the thu'um. Auri-El in my narrative is the Elven version of Akatosh, so he, yes, in my narrative, created dragons. While they cannot directly interfere, they can cause happenings. Auri-El and Kyne participate in the reforging of Wuuthrad by creating weather elements. Both aedra speak to my protagonist in dreams, but why they are able to do this with him would be a huge spoiler and I can't say, though if you read Chapter I, I do give a huge clue. No, he's not a god, far from it. I do go pretty deep into dragons and stuff.
Kyne, not Kynareth, but Kyne is curiously missing from any Elven pantheon. They opted for Mara instead. Interesting, no, but considering she allies herself pretty strongly with men, it's not surprising. The irony is that Stendarr makes to the Elven pantheon and he is called the apologist of men. My character does not worship the Divines of the Cyrodiilic empire.
Daedra did not contribute to the formation of Nirn and therefore retained their power and dwell in Oblivion. They do not have a general moral alignment, though some are quite evil (Dagon, Bal), others are more ambiguous. All do much more manipulation in mortal lives that Aedra typically do.
Aedra - ancestors, were those who were involved somehow in the creation of nirn as conceived by Lorkhan. Original chilren of Anu and Padomay. Daedra came from those two as well.
Aetherius - the immortal plane, and it is divided into realms of which Sovngarde is a part. My character can travel to various realms in dreams. He visits Kyne's realm, and yes, eventually Sovngarde as he advances in the story. Now why? Cause, it's pretty heavily implied in gameplay, at least in Skyrim, anyway that the Dragonborn is an aspect of Shor. Shor rules Sovngarde, so well, this allows the Dragonborn access. You will also note that Shor is curiously missing from his throne in Sovngarde and nobody says ANYTHING when your dragonborn slaps his/her little butt down on it. 
There is also the concept of reincarnation that you're missing, the Dreamsleeve. My character is also a priest, so he deals with burial and the dead, since Arkay is not present in his Pantheon, I rationalize that since Auri-El is the god of time, and life and death are governed by it, members of his Order handled funeral rights.
Oblivion - the immortal plane of the Daedra and also comprised of realms. My character does cross into planes of Oblivion, but I change his form to do so. Again, big spoiler I can't reveal.
Not sure what happened to the Dwemer. They do not play a large part in my narrative. Other extinct species do, specifically the Snow Elf. I couldn't put everything in my narrative. LOL
Well, from what I understand of the lore, magicka is the crap Magnus left behind when he bee-lined out of nirn, abandoning his project and headed back to Aetherius. Him, crossing over, left the sun. Other lesser Aedra crossing back became the stars. It is curious to me that Auri-El's symbol is also the sun and the Eagle. Now the eagle is interesting and it is also interesting to note that Skyforge is in the shape of an eagle. I take that idea and run with it. I run with it super far.
The picture in that link would be a very Cyrodiilic concept of Nirn. At least in my eyes. I think the Altmer view would differ significantly, with Auri-El occupying a much higher position, closer to Magnus.
If any of this made any sense to you, let me know. If it didn't let me know.
EDIT: GOOD LORD, am I insane. I wrote a damn novel.
Not sure how well I can answer. Do you want definitions or how we tie it into the worlds we create? I'll sort of tie it to the world I've created. I delve pretty heavily into the lore in my narrative, well as much of it as I can.
In my narrative, the Aedra are beings that participated in the creation of Mundus the mortal plane. They are weakened after this, however, many of them are still considerably powerful in the Dawn Era as they do lead massive armies, (Auri-El, Trinimac, Kyne, Lorkahn). They are still revered in the various pantheons. Auri-El is particularly significant as he is the Aedroth that my character most reveres and is a member of his order. The goal of the order is to ascend into Aetherius as Auri-El illustrated by ascending to Aetherius himself. Other aedra that figure in include Kyne, the widow of shor/lorkhan and the one who convinced Paarthurnax to give the thu'um. Auri-El in my narrative is the Elven version of Akatosh, so he, yes, in my narrative, created dragons. While they cannot directly interfere, they can cause happenings. Auri-El and Kyne participate in the reforging of Wuuthrad by creating weather elements. Both aedra speak to my protagonist in dreams, but why they are able to do this with him would be a huge spoiler and I can't say, though if you read Chapter I, I do give a huge clue. No, he's not a god, far from it. I do go pretty deep into dragons and stuff.
Kyne, not Kynareth, but Kyne is curiously missing from any Elven pantheon. They opted for Mara instead. Interesting, no, but considering she allies herself pretty strongly with men, it's not surprising. The irony is that Stendarr makes to the Elven pantheon and he is called the apologist of men. My character does not worship the Divines of the Cyrodiilic empire.
Daedra did not contribute to the formation of Nirn and therefore retained their power and dwell in Oblivion. They do not have a general moral alignment, though some are quite evil (Dagon, Bal), others are more ambiguous. All do much more manipulation in mortal lives that Aedra typically do.
Aedra - ancestors, were those who were involved somehow in the creation of nirn as conceived by Lorkhan. Original chilren of Anu and Padomay. Daedra came from those two as well.
Aetherius - the immortal plane, and it is divided into realms of which Sovngarde is a part. My character can travel to various realms in dreams. He visits Kyne's realm, and yes, eventually Sovngarde as he advances in the story. Now why? Cause, it's pretty heavily implied in gameplay, at least in Skyrim, anyway that the Dragonborn is an aspect of Shor. Shor rules Sovngarde, so well, this allows the Dragonborn access. You will also note that Shor is curiously missing from his throne in Sovngarde and nobody says ANYTHING when your dragonborn slaps his/her little butt down on it. There is also the concept of reincarnation that you're missing, the Dreamsleeve. My character is also a priest, so he deals with burial and the dead, since Arkay is not present in his Pantheon, I rationalize that since Auri-El is the god of time, and life and death are governed by it, members of his Order handled funeral rights.
Oblivion - the immortal plane of the Daedra and also comprised of realms. My character does cross into planes of Oblivion, but I change his form to do so. Again, big spoiler I can't reveal.
Not sure what happened to the Dwemer. They do not play a large part in my narrative. Other extinct species do, specifically the Snow Elf. I couldn't put everything in my narrative. LOL
Well, from what I understand of the lore, magicka is the crap Magnus left behind when he bee-lined out of nirn, abandoning his project and headed back to Aetherius. Him, crossing over, left the sun. Other lesser Aedra crossing back became the stars. It is curious to me that Auri-El's symbol is also the sun and the Eagle. Now the eagle is interesting and it is also interesting to note that Skyforge is in the shape of an eagle. I take that idea and run with it. I run with it super far.
The picture in that link would be a very Cyrodiilic concept of Nirn. At least in my eyes. I think the Altmer view would differ significantly, with Auri-El occupying a much higher position, closer to Magnus.
If any of this made any sense to you, let me know. If it didn't let me know.
EDIT: GOOD LORD, am I insane. I wrote a damn novel.
