​"Mindfulness is...
   ...the awareness that emerges through paying attention on purpose, in the present moment, with compassion and open-hearted curiosity."

Oxford Mindfulness Centre, Oxford University

"Mindfulness means deliberately paying attention, being fully aware of what is happening both inside yourself--in your body, heart, and mind--and outside yourself in your environment. Mindfulness is awareness without judgment or criticism. The last element is key. When we are mindful, we are not comparing or judging. We are simply witnessing the many sensations, thoughts, and emotions that come up as we engage in the ordinary activities of daily life. This is done in a straightforward, no-nonsense way, but it is warmed with kindness and spiced with curiosity."

From the chapter "What Is Mindfulness?" by Jan Chozen Bays in The Mindfulness 

Video is by the Center for Mindfulness in Medicine, Health Care and Society (CFM), UMass School of Medicine. See more CFM videos here.