Concentration

From: Eternity's Breath by Sri Chinmoy

Concentration is the Arrow.
Meditation is the Bow.


When you concentrate, you focus all your energies upon the
chosen phenomenon in order to unveil its mysteries.
When you  meditate, you rise into a higher consciousness.


Concentration wants to penetrate into the object it strives for.
Meditation wants to live in the vastness of Silence.

Concentration is a very important quality on the path. There are quite a few exercises to improve it. The Dot is a classic Yoga exercise to improve the power of concentration. There are a few variants around, but I feel Sri Chinmoy's version is the best, at least for me. Here it is.