Definition: Index Frameset: A template that represents a list or array of items in HTML, typically used to format images, buttons, or other forms of content. Definition: A template file created for a specific purpose, often within a specific framework or library, which is designed to be rendered by the application it serves. The index frameset template allows you to define and use various data structures such as arrays, lists, or numbers, while keeping them easily accessible through the application's user interface.