Hydroponic means "Working Water", to put it simply: Growing IN water. No soil, the nutrients go directly into the water.
There are ups and downs to a Hydro system.
Space is a bonus
Easier to tell when to water
You can directly decide how much nutrients your plants get
Less chance of fungus, since water moves.
Plants are easier to kill in water, if you don't know what your doing
you HAVE to know what your doing, nute levels and everything, are
critical in a hydro grow. The water is much less forgiving to the MJ
plant than soil is.