This is the 80th most frequent Japanese word.
活動
"Activity" or "action."
In this sentence, '活動' refers to organized group efforts, specifically volunteer-related activities in this case.
彼はボランティア活動に参加しています。
He is participating in volunteer activities.
Here, '活動' implies endeavors or initiatives such as campaigns or projects aimed at protecting the environment.
環境保護の活動は非常に重要です。
Environmental protection activities are very important.
In this example, '活動' simply represents the general daily routines and tasks performed, highlighting its versatility.