What is the purpose of a VDU?

The purpose of a VDU, or Visual Display Unit, is to present temporary output from a computer, which makes it a critical component in human-computer interaction. When a user interacts with a computer, the VDU allows for the visualization of data, graphics, and interfaces in a user-friendly manner.

Unlike storage devices that retain information over long periods, a VDU displays dynamic content generated by the computer's processing in real time, enabling users to view and interact with their tasks, documents, or applications on screen. This temporary display is essential for activities such as editing documents, programming, or designing, where immediate visual feedback is required.

In contrast, other options relate to functions that are not part of what a VDU does. Data storage, speed enhancement, and backup memory involve different hardware and functions that are not associated with the primary role of a VDU. Thus, the correct understanding of a VDU's purpose emphasizes its role as a medium for temporarily displaying data processed by the computer system.