One-pointedness denotes complete focus on a single object. In Sanskrit, this concept is translated as Ekaggata. It is one of the teachings in Buddhist meditation.
I hadn’t heard of one-pointedness until yesterday. Often, when I meditated, I would try (typically unsuccessfully) to empty my mind completely. The concept of one-pointedness makes me think otherwise. I shouldn’t be trying to obtain simply a blank slate, but rather, a blank slate with a single point of focus.
It makes sense if I give you an example. One of the anchors (the single point of focus) used to teach this is the breath. I have continuously heard meditators talk about focusing on the breath, but what part of it? There are so many different aspects of breathing. Should I focus on the expansion of the diaphragm or the sound created by inhaling and exhaling?
One-pointedness offers a specific point of focus that you may have never even noticed before: the subtle sensation of breath as it enters the nostrils. Do you feel that? That slight stirring of air when reversing the direction of your breath, from an inhale to an exhale?
I believe what makes this particular point of focus so effective is how easy it is to go unnoticed. Only with such a minuscule sensation can we actually focus on a single point.