Basically lucid means aware. So if you are aware you are dreaming while dreaming you are in a lucid dream. Although this can happen naturally folk want to learn more HOW TO TAKE CONTROL.. You could be in a lucid nightmare and want to upgrade that to a lucid dream which the prime difference is YOU are in control. Make no mistake the dream or the nightmare come from your own mind and your own hopes fears desires and whims. So being in control of your own emotions is key to controlling your dreams.