The essence of mindfulness is being in the moment, being increasingly present and aware in the current situation, and observing external and internal stimuli with acceptance instead of judgement.
Definitions of Mindfulness
“Bringing one’s complete attention to the present experience on a moment-to-moment basis.” (Marlatt & Kristeller)
“Paying attention in a particular way: on purpose, in the present moment, and non-judgmentally” (Kabat-Zinn).
“The non-judgmental observation of the ongoing stream of internal and external stimuli as they arise.” (Baer)
“Awareness of present experience with acceptance.” (Germer, Segal, Fulton)
“Paying attention with openness, curiosity and flexibility.” (Rusell Harris)