The Retrospective is one of five events in Scrum. It’s purpose is to inspect the whole Scrum Team from the perspective of people, process and tools, and then adapt the way the whole team works (including the Product Owner).
The Sprint Review is one of five events in Scrum. It’s purpose is to inspect the Increment of work, get feedback, and then adapt the Product Backlog. And while many people refer to the Sprint Review as the “demo” or “showcase”, this is only one aspect of the Sprint Review.
Many people use the Daily Scrum to provide a status report to the Product Owner or Scrum Master, and even to stakeholders, but this event plays a more critical part in ensuring that the team continues to stay focussed on their goal and adapt their work so they improve their chance of achieving it.