Welcome to Dream Views! I have put together a simple list you can refer to when you run into acronyms like WILD, HH, or RC. The concepts are kept extra basic on purpose. All of the induction techniques end with ILD which stands for such and such Induced Lucid Dream.
LD: Lucid Dream
IRL: In Real Life, could be IWL in waking life.
WILD: lucid dreams that you enter after having been awake, as you fall asleep, or using some method like visualizing or deep trance like meditation. The W stands for wake, as in awake, so just remember that.
DILD: lucid dreams that happen because you figure out that you are dreaming and become lucid in the middle of a normal dream. The D stands for Dream.
MILD: Any mental trick that helps someone have DILDs. A DILD may often be called MILD if the dreamer did something to encourage it. (don't worry about the M for now)
DEILD: a lucid dream you get by laying still when you first wake up and trying to return to the dream you were just having. The DE stands for Dream Exit.
RC: Reality Check. This is when you stop and try to find out if you are dreaming or not. People who use RC are hoping to have it help them achieve DILDs. That makes RC a form of MILD. The idea is that if you question this during the day enough, then you will start questioning it during a dream.
REM: Rapid Eye Movement is a state of sleep where many vivid dreams occurs. Named for rapid eye movements that happen during it.
nREM: any state of sleep that is not REM. You can still dream in nREM but it is less common.
SP: Sleep Paralysis. Waking up and not being able to move, or something similar. Often talked about in WILD threads because some people experience it when trying this type of lucid dream. Uncommon.
REM atonia: Experiencing the same chemical effect that causes people to stay still when they dream. Easily broken by concious effort. Experienced sometimes in WILD attempts. SP is often caused by something going wrong with REM atonia, but that is uncommon.
HH: Hypnogogic Hallucinations. Any wierd stuff that takes place in your head when you are half asleep. This may be voices or vibrations or colorful images, or many other variations. Also may be called HI for hypnogogic images.
WBTB: Wake, Back to Bed. This involves waking up anytime after about 5 hours of sleep on purpose, with the intent of going back to sleep while focusing on lucid dreams. People do this because they have a better chance of being aware in REM as the night progresses.
FA: False Awakening. It is common to lose a lucid dream because you dream that you woke up. It is always a good idea to question if you have really woken or not, if you wake from a lucid dream. You may still be dreaming, but be fooled into losing lucidity.
DC: Dream Charactor. Any of the people or animals you interact with inside a dream.
DJ: Dream Journal. http://www.dreamviews.com/blogs/