"One Word shows the way to the simplicity of focus. It gues you to what should currently matter most and clarifies how to live from that place." The idea is simple - discover your one word for the yar, own it, live it, and experience its impact on your life.
Eliminating what is non-essential is a way of filtering through noise until you get to 'the essence.' The way of the Essentialist is the relentless pursuit of less but better. It means pursuing it in a disciplined way. Thsi includes puasing constantly to ask "Am I investing in the right activities?'