The Overlay PDFs feature allows users to overlay multiple PDF documents together and set overlay modes and positions. This is useful for users who need to merge multiple PDF documents into a single document. For example, in academic research, users may need to overlay multiple papers or reports together for comparison and analysis; in enterprise document management, users may need to overlay multiple manuals or guides together for employee reading and use. Additionally, this feature can be used to overlay multiple contracts or agreements together for better management and auditing. By using the overlay PDFs feature, users can ensure document content merging and display and easily manage and distribute them.