A data layer is a structured way to organize and manage information in a digital environment. It acts like a bridge between different systems, allowing them to communicate and share data effectively. For example, in web development, a data layer can help track user interactions on a website, making it easier to analyze visitor behavior and improve user experience. In marketing, a data layer can enhance the use of tools like Google Tag Manager by providing a consistent format for data collection. This ensures that all relevant information, such as user demographics and purchase history, is captured accurately, enabling businesses to make informed decisions based on reliable insights.