A Data Layer is a structured way to manage and organize data on a website or application. It acts as a bridge between the user interface and the underlying data sources, allowing developers to easily access and manipulate data without directly interacting with the backend systems. This separation simplifies data management and enhances the overall performance of the application. In web development, the Data Layer is often used in conjunction with tools like Google Tag Manager to track user interactions and gather analytics. By standardizing data formats, it ensures that different systems can communicate effectively, making it easier to implement changes and updates across the platform.