The presentation layer is the topmost layer in the OSI model, which is a framework used to understand network communication. Its primary role is to format and present data to the user or application, ensuring that information is displayed in a readable and understandable way. This layer handles tasks such as data translation, encryption, and compression, making it essential for effective communication between different systems. In web development, the presentation layer is often associated with the front-end, which includes everything users interact with directly, such as HTML, CSS, and JavaScript. This layer is responsible for the visual aspects of a website or application, ensuring that users have a seamless experience while accessing information or services.