Concentration and mindfulness are different from each other.
There are a few levels of concentration. We can concentrate on something such as our studies or sports. That would be a concern or a focus. Sometimes we say that we need to concentrate on just one thing. We have lots to do, but we need to concentrate on one particular thing. Concentration is also power. If we want to have our own business we find a way to do it. If a person believes in something enough that person can do that.
Mindfulness can be the result of concentration. For example, we usually concentrate on breath when we meditate. In present moment ( this class ) we just let whatever arise and don't be involved. Things we usually concentrate on are past, future, imaginings, and dreams. Being mindful means that we have an awareness of what is existing now.
To the Buddha mindfulness is more important than concentration because a person can become blinded with just concentration. Can become mesmerize.
We are very powerful. If we believe in something it can be very real. For example, if we use a thermometer in our hand and we think about being hot, it will heat up. That is the power of our mind.
That power can be wrong because of the blindness it causes. For example, if someone goes fishing they can spend along time at it and be very happy. However, from the fish point of view that is harmful. We are blinded by our concentration on fishing.
We cannot developed mindfulness without concentration. The are two words for concentration and mindfulness. Respectively "Samatha" concentration and "Vipassana" insight. The power leads to insight. First we concentrate and have power then that power transfers to our mindfulness. It gives us the chance to control our emotions or thoughts and see things without being attached to them. It leads to powerful understanding which also is known as spiritual power.
So, how does one go about this concentration to mindfulness meditation?
The experience for the person who practiced concentration first will be very different than a person who practiced mindfulness first. If a person is not settled in meditation it is better to practice concentration first. When a person is settled they can move toward mindfulness.
The Budda practiced concentration before he was enlightened. Then he practice his own technique. On the last day before being enlightened he started with breathing and then he moved to mindfulness or awareness towards breath . He then became enlightened / awakened.
Breathing is the only technique one can apply to both concentration and mindfulness. There is no switch. It happens on its own. Don't involve and don't react.
Constrentins practice will give strength to develop mindfulness, mindfulness will clean your mind from blindness it will bring you wisdom.