I see lots of posts on here about being "semi-lucid" or being aware you are in a dream, but not really "being aware" or having control. I have used this to answer a few peoples questions here and there. So I decided to post this collection of info I have gathered about the various levels of lucidity.

in my experience there are various levels of lucidity. it can get a bit confusing sometimes, especially if you are having a dream about having a lucid dream. this fellow Reece Jones (who I believe is registered here but does not seem to be an active member) has done some videos on it and broken it down into reasonable subdivisions. i tend to agree with his synopsis for the most part, though the major and minor layers kind of complicate things. I have copied and pasted his breakdown below.

check out these videos:
The 5 Layers of a Lucid Dream (1/5)

Also, there is an excellent thread by Arby about it here, with a similar but slightly different breakdown.
http://www.dreamviews.com/f11/levels-lucidity-36173/

A Brief Summary

Layer Zero (Minor):
Engaging in lucid dream discussion without becoming lucid.
Seeing lucid dreaming related material without becoming lucid.
Thinking about lucid dreaming related material without becoming lucid.
One or all of these criteria can be met for it to classify as Zero (Minor).

Layer Zero (Major):
Nothing feels quite real within the dream, yet you never become fully lucid.
You get the sense that theres no consequences or repercussions, yet you never become fully lucid.
You get the sense that you can reset or stop the experience entirely, yet you never become fully lucid.
One or all of these criteria can be met for it to classify as Zero (Major).

Layer One (Minor):
You become lucid and then startle yourself back to waking life within seconds.
You're in a nightmare of sorts, you realise you're dreaming and choose to wake yourself up.
One or both of these criteria can be met for it to classify as One (Minor).

Layer One (Major):
You become lucid and within seconds you have a false awakening and carry on non lucid.
You become lucid and within seconds you fade to the black (not fully awake) and eventually re-enter non lucid.
One or both of these criteria can be met for it to classify as One (Major).

Layer Two (Minor):
You'll realise you're dreaming, although you won't fully understand the implications of what dreaming really is. The dream will be fairly unstable (flickering scenery, blurry textures, etc). You'll not have full control over your actions and at points it may feel like you're watching a movie. Dream characters are not aware that they're merely dream characters. You also still feel as if the dream characters are real people.

You realise that you're dreaming, but don't care enough to try and take control.

Layer Two (Major):
You'll realise you're dreaming, although you won't fully understand the implications of what dreaming really is. The dream will be fairly unstable (flickering scenery, blurry textures, etc). You'll not have full control over your actions and at points it may feel like you're watching a movie. You still feel as if the dream characters are real people. Although, ironically, they seem to realise that they're just dream characters. They seem to have more awareness than you!

A dream character informs you that you were dreaming earlier on in the dream. You believe this, but don't think to check if you're still dreaming now.

Layer Three (Minor):
You'll realise you're dreaming and fully understand the implications of what dreaming really is. The dream will be stable and vivid. However, you'll not have full control over your actions and at points it may feel like you're watching a movie. You understand that the dream characters are merely a facet of your imagination, although they still believe that they're real.

When you become lucid, you understand the full implications, but youre not in total control. Because youre watching it unfold without any real influence over it, you become so immersed in the dream you lose lucidity. Later on you regain lucidity and remember how earlier on in the dream you were also lucid.

Layer Three (Major):
You'll realise you're dreaming and fully understand the implications of what dreaming really is. The dream will be stable and vivid. However, you'll not have full control over your actions and at points it may feel like you're watching a movie. You understand that the dream characters are merely a facet of your imagination, and they also understand this.

You realise that youre dreaming and understand the full implications, but consciously make the decision to not interfere and instead, you let it run its course. So, it may be like watching a movie again. But youve chosen for it to be that way.

Layer Four (Minor):
You realise that youre dreaming, and the full implications of what dreaming really is will sink in. The dream will also be very stable and vivid. You will also have full control over your actions. However, dream characters will not be aware that it is a dream.

Layer Four (Major):
Full control. Unity. All dream characters aware. Stable and vivid. From here its easier to enter OBEs.