Kundalini energy is
the energy of your being which sits at the base of your spine, in
the root
chakra.
It wakes up when you start meditating,
visualizing or doing other spiritual activities.
When activated, kundalini
energy starts going up your
chakras till
it reaches the crown chakra and when it goes through the crown
chakra the person becomes enlightened.
This energy can either be awakened unnaturally by gurus and
meditation experts or it naturally awakens when the person develops
spiritually