According to this WikiHow tutorial on How to Lucid Dream, The most basic definition of lucid dreaming defines it as being aware you are dreaming while dreaming.

the article then says that t is possible to control your dreams by employing the lucid dreaming methods that follow. They list a variety of ways.

Lucid Dreaming expanded on Google DMOZ

Here is an excerpt: A lucid dream is simply one in which you realize that you are dreaming. The dream I just described happened about a year ago—and it happened spontaneously, without any effort or intention on my part. Since then, I’ve read about and practiced a variety of methods for inducing lucid dreams deliberately. Although I can’t yet dream lucidly on command, my success rate has gradually improved. For me, this is a purely recreational activity, but for centuries lucid dreaming, in one form or another, has been practiced with great seriousness in certain religious and philosophical traditions. Tibetan Buddhism, in particular, has an ancient discipline of meditative techniques designed to encourage not just lucid dreaming, but a continuously unbroken state of consciousness, while sleeping and awake.

What’s so great about lucid dreaming? For one thing, it’s lots of fun. If you’re aware that you’re dreaming, you can do things that are impossible in waking life, such as flying, becoming invisible, or traveling to distant times or places. But on a more practical note, interacting with dream characters in a lucid state can help the dreamer to interpret the meanings of dreams in real time. Lucid dreams can also enable the dreamer to find creative solutions to problems, work through difficult emotional issues, and promote physical and mental healing. Many people believe lucid dreaming is a path to, or at least a necessary step toward, a form of enlightenment, and it also forms part of the training for some forms of shamanism.

Wikipedia, the free encyclopedia explored lucid dreaming