Here are my definitions of Astral Projection, Etheric Projection, and Lucid Dreaming. This way, people who have been wondering can see the differences.
There are also other forms of projections, such as Mental Projection, and Bilocation. Bilocation is quite complicated.
In AP, your 'conciousness' and 'astral body' separate from the physical body and the Physical Realm, going into the Astral Realm. You kinda have a sense like your floating. You have use of all your five senses, plus the ones given to you in your astral body. When you have very vivid dreams, this is usually a form of accidental, natural AP.
AP is 100% safe, and nothing can enter your physical body when you are in AP. If theres any sign of danger, you get 'reeled in' quickly. Ever had a dream where you're falling off something and wake up just before you hit the ground? Yep. Very similar to that. ^_^
Etheric Projection is when your etheric body separates from your physical body. Etheric Projection is a OBE or usually when you have a NDE, and they stand for Out of Body Experience and Near Death Experience. It can be dangerous if you go into shock or are disturbed, and that can cause physical death, which rarely happens.
You have all your 5 senses; and you are technically still in the Physical Realm.
Okay, firstly, contrary to popular belief, Lucid Dreaming is not controlling your dreams. It is simply the awareness that you are dreaming. Hence the 'lucid' part. Personally, I dont think it requires more definition, because that is all it is. The awareness that you are dreaming; and also, you're still in the Physical Realm.