Zazen is meditation. Zen is practicing zazen. Although there are lots of benefits you can get from Zen without practicing zazen, there are probably more benefits you can get from practicing zazen without practicing Zen.
The philosophy of Zen is helpful in exposing all kinds of ideas we have about life, love and everything that are simply wrong. Things that we count on to bring us pleasure actually bring us pain. Things that we think bring us pain actually don’t exist. The ideas of Zen can help us to pay attention to all our other ideas to see which ones cause us pain and which ones relieve the pain.
Zazen just throws out all of the ideas for a little while. Sit, breathe, sit, experience. When the ideas stop coming, the judgements stop, good and bad are gone, happy and sad are gone, there is just sitting.
The philosophy of Zen tells you that by sitting you can transform your life and transform the world. That may happen, but when you sit, you don’t have to worry about that. Just sit, breathe, sit. That’s enough.