During meditation, your brain is anything but switched off. Different networks are involved depending on how you meditate. In meditations with a clear focus, these include areas connected with attention, self-awareness, and the control of thoughts.1
The so-called Default Mode Network is studied particularly often. Among other things, it is active when our minds wander or when we think about ourselves. During focused attention, parts of this network often show less activity. When you notice that your mind has wandered and bring your attention back, networks that control attention become involved in turn.2
Regular meditation is also associated with changes in how different brain networks work together. What these changes mean in the long term, however, is not yet fully understood.1