Concentrate

Example: "The country's population is concentrated in major cities".

Focus, center, rivet, attend, or "pore over". For gathering: Accumulate, amass, congregate, or cluster. concentrate

If you are looking to improve your personal focus, research-backed strategies include: Tips to improve concentration - Harvard Health Example: "The country's population is concentrated in major

To bring or gather things together in one place or toward a common center. or "pore over". For gathering: Accumulate