Each of the Kua (or Gua) represent the energies of the universe and has a Pa Kua meaning associated with it.
Qian Kua is the symbol of heaven. It is pure Yang energy and represent the creator, father, male, active, virile etc.
Kun Kua is the symbol of the earth. It is pure Yin energy and represent responsiveness, mother, female, passive, yielding, quiet etc. Qian and Kun by themselves do not result in anything but when combined create a variety of things.
Li Kua is the symbol of fire. It represents heat, light, radiating and the color red. It implies intelligence, wisdom and justice.
Kan Kua is the symbol of water. It represents danger, difficulty, sinking, below and the color blue and black. It implies darkness and also represent the moon.
Zhen Kua is the symbol of thunder. It represents the initiating energy. Qian creates but it is Zhen that makes things grow.
Xun Kua is the symbol of the Wind. It represents penetrating energy. It implies proceeding gently like the tree penetrating the ground.
Ken Kua is the symbol of the Mountain. It is the energy that compliments Xun. It sooths the penetrating energy. It implies stillness, resting, halting etc.
Dui Kua is the symbol of Lake (or rice field). It represents joyful energy, pleasing, cheerfulness, delighting and happiness.