What is the meditation and what is its purpose? Is meditation thinking about thoughts?
Is it rational thinking about our perceptions?
What is meditation? What is the purpose of it?
Can I gain supernatural powers via meditation?
Meditation is when the mind comes back home. When the mind comes back home it can sit by the fire and enjoy its own warmth. It can stop being busy with all kinds of "doing". Meditation is the ultimate "not-doing". Just sit in presence and let the nature of things take care of itself.

Meditation is not thinking. It's more like watching the cows graze. The cows represent thoughts, if they start misbehaving you show them their place -- other than that, you just let them graze. When the mind watches itself, there is some processing going on, some laundering, some mending and healing, some connecting, some letting go.

The practical purpose of meditation, beside processing, mending and healing, is to reunite with the original state of "this is enough", "this is peaceful". The supramundane purpose of meditation is to lose form and go deep into formless, the real nature of things.

When you completely lose attachment to any form, you get supernatural powers - yes.