What is Meditation? based on Yoga Psychology book written by Shrii Shrii Anandamurti
Summarized by Acarya Shubhacetanananda Avadhuta

Mind thinks, discovers and invents. The mind thinks with concentration that is the mind meditates. With spiritual progress the mind develops in greatness.
Meditation means focused thinking associated with numerous subtler and significant cells of the human brain.
Thinking in a systematic way gives positive effect. If mind does not think in a methodical way, it has negative outcome.
Thinking means a special kind of quality that separates from one object to others.
Thinking is the subjectivity of external objectivity that creates an external object with one’s mental plate and makes it a part of one’s internal existence. Mental flow is concerned with theory and practice.
How can one develop focused thinking?
According to Yoga Psychology written by Shrii Shrii Anandamurti, thinking with concentration is meditation. People should practice meditation knowing well the positions of glands with their corresponding system of hormone secretion. Otherwise their meditation will not produce any outcome.
Therefore the knowledge of biology is essential to progress in meditation.
Yoga Sadhana, meditation is a process to unite unit consciousness with the Supreme Consciousness.
People can get practical experiences by joining the Rajadhiraja Yoga meditation classes.