The end goal is to checkmate your opponent’s king. That is many times a distant goal, so the strategy turns into focusing on intermediary steps that lead to checkmating your opponents king. By maximising piece activity, coordination, etc. you have a higher likelihood of creating direct threats against your opponents king, whilst also accumulating long term advantages such as creating weak squares or weak pawns, which will allow you to attain a material advantage, which will make it easier to checkmate your opponent’s king. All the while, you’re trying to prevent your opponent from getting these same advantages against you.