Here. Now! Mindfulness is the ability of keeping the mind engaged with whatever arises in the present moment, without getting too attached or fascinated by it.
The ability to keep calm and composure in the face of great adversity! Equanimity develops as a result of the practice and offers a different quality of life.
Concentration is an advanced practice that allowed the meditator to sit for longer. It is similar to the state of flow. I personally feel it most when I stream or scalp.