"Mindfulness is a translation of a word that simply means awareness. It's a direct, intuitive knowing of what you are doing while you are doing it. It's knowing what's going on inside your mind and body, and what's going on in the outside world as well.
Most of the time our attention is not where we intended it to be. Our attention is hijacked by our thoughts and emotions, by our concerns, by our worries for the future, and our regrets and memories of the past. Mindful awareness is about learning to pay attention, in the present moment, and without judgement. It's like training a muscle - training attention to be where you want it to be. This reduces our tendency to work on autopilot, allowing us to us choose how we respond & react."
~ Mark Williams
Source: http://www.mindfulnet.org