There are several different kinds of dreams, including lucid dreams. Another type of dream is a vivid dream, which includes images that are very clear or realistic. Nightmares are a type of bad dream that can make people wake up. There are also recurring dreams, which are when people dream about the same thing more than once (Suni).

Which extended definition would be most helpful to add to this body paragraph?

Lucid dreams are not very common.
Lucid dreams are still a bit of a mystery.
Lucid dreams are one of several different kinds of dreams.
Lucid dreams are when the dreamer knows they are dreaming.