Seated meditation, zazen in Japanese, is the heart of practice. By practicing zazen, you return, over and over again, to the present moment. This is accomplished by turning your attention to sensations of the body – the breath, the body, sounds.
Our minds are often in the future planning for what's next, ruminating on events of the past, or spacing out in fantasy. Because the body can only be in the present moment, the body is used as an anchor to bring awareness again and again back to your direct experience, setting aside judgment or opinion.
This is simple, but not easy! Just like learning anything new, by practicing we become more confident and skillful. Then we challenge ourselves to investigate even more deeply.
The great Japanese master Dogen Zenji said that "zazen is the Dharma Gate to ease and joy." How is this so? We practice zazen to see for ourselves.