Out of body experiences? Astral projection?

Hey guys, so i've heard about " out of body experiences" and stuff, but i never really took into account what it means? I'm not so sure what i believe to be honest with you? Is it all rubbish or is it real? It is when you are sleeping and have a good imagination that causes it? Or can you do it consciously? Also is it safe? and how could i do it? I'm a bit scared by the thought of it, because i don't imagine it to be safe? But it sounds so very true with peoples experiences? Is there an age or anything? Daylight or nighttime? when is best, i would like someone to tell me how to do it if it is real. But i cannot imagine for it to be scientifically possible? Why can't we just all do it ourselves? I don't understand it and i find it a little creepy... but of course i would love to try it? Is it just a trick of the mind or is it really possible? Thanks guys! x sorry it's a bit long!