This is the 230th most frequent German word.
darüber
"Darüber" means "about it" or "over it" in English.
In this context, 'darüber' refers to the topic or matter being thought about, connecting 'denken' to the subject of the thought.
Ich denke oft darüber nach, wie ich meine Ziele erreichen kann.
I often think about how I can achieve my goals.
Here, 'darüber' is used to indicate the content or matter of the information given.
Er hat mich darüber informiert, dass der Termin verschoben wurde.
He informed me that the appointment has been postponed.
In this example, 'darüber' acts as a reference to what the discussion was about, specifying the subject matter.