Buddhism, or Buddhadharma, is Buddha’s teachings and the inner experiences or realizations of these teachings. Buddha gave eighty-four thousand teachings. All these teachings and the inner realizations of them constitute Buddhadharma.
Buddhadharma does not stay in one place but moves from one country to another. Just as gold is precious and rare, so Buddhadharma is precious and very hard to find.
Buddha taught how to examine our mind and see which states produce misery and confusion and which states produce health and happiness. He taught how to overcome the compulsively non-virtuous minds that confine us to states of discontent and misery, and how to cultivate the virtuous minds that liberate us from pain and lead us to the bliss of full enlightenment.
By learning Buddhadharma, we will have the opportunity to gain the happiness we seek and to fulfil all our temporary and ultimate wishes.
You can learn more about the mind and how to control it from How to Understand the Mind.