Improvement, Betterment
noun, verbal noun, の adjective
When you renew something and it ends up morally good it's definitely an improvement.
かいぜん
This is a jukugo word, which usually means on'yomi readings from the kanji. If you know the readings of your kanji you'll know how to read this as well.
このシステムにはまだ改善が必要です。
This system still needs improvement.
ユーザーのフィードバックを元に、サービスを改善しました。
Based on user feedback, we have improved our services.
このミーティングは、プロジェクトの改善点を話し合うためのものです。
This meeting is to discuss improvements to the project.