In his bestselling book Flow: The Psychology of Optimal Experience, Hungarian psychologist Mihaly Csikszentmihalyi defines flow as
“a state in which people are so involved in an activity that nothing else seems to matter; the experience is so enjoyable that people will continue to do it even at great cost, for the sheer sake of doing it.”
Flow is the ultimate form mindfulness in action. You are completely engaged to the extent that all distractions fall away, and you are one with the task at hand. This is the state of mind you want to achieve with any focused effort you perform at work or in your personal life.