To grasp or understand something (e.g., the situation, meaning, or main points); can also mean to hold or seize firmly. Often used as 把握する.
まず現状を正確に把握する必要がある。
First, it is necessary to accurately grasp the current situation.
要点を把握してから報告書を書いた。
I wrote the report after grasping the main points.
彼は道具の持ち方をしっかり把握している。
He has a firm grip on how to hold the tool.