Yoga is the process of quieting the mind.
More explicitly, yoga is a system of values, exercises, and contemplative techniques that, over time, can lead to a healthier body and mind.
Here is a beginner-friendly video introducing some simple chair-based exercises to begin your practice.
These exercises serve two purposes: 1) to help relax the body and nervous system and reduce stress, and 2) to make it more comfortable to sit and meditate.
Quieting the mind helps clarify what is essential and what is clutter.
By clutter, I mean anxiety—ruminating about the past and catastrophizing about the future.
One of the simplest ways to meditate is to sit and focus on the breath.