Final answer:
The term for making an opposite selection from a selection is 'Inverse'. This is commonly used in technology when a user changes their selection or toggles between options.
Step-by-step explanation:
The term for the action a user must perform to make an opposite selection from a selection is Inverse. In the context of computer science or technology, when a user selects an option, the inverse action would deselect that option, or select the opposite if it's a binary choice. For example, if a specific range of text is highlighted (selected) in a document or a specific set of files is selected on a computer, applying an inverse action would deselect that text or those files. Similarly, if a user applies a filter to search results, using the inverse function typically removes that filter to show all results again.