At its heart, Scrum works by breaking large products and services into small pieces that can be completed (and potentially released) by a cross-functional team in a short timeframe. Scrum teams inspect each batch of functionality as it is completed and then adapt what will be created next based on learning and feedback, minimizing risk, and reducing waste. This cycle repeats until the full product or service is delivered—one that meets customer needs because the business has the opportunity to adjust the fit at the end of each timeframe.
For a more thorough explanation of how Scrum works, consult the Scrum Guide.