A conceptual layer refers to an abstract level of understanding or representation in a system, often used in fields like software development and data modeling. It helps to organize and simplify complex information by breaking it down into manageable parts, allowing for easier communication and analysis. In computer science, a conceptual layer can represent the relationships between different components, such as databases and user interfaces. This layer acts as a bridge, ensuring that changes in one part of the system do not disrupt others, thereby enhancing flexibility and maintainability in design and implementation.