3.2.4 Consistent Identification: Components that have the same functionality within a set of Web pages are identified consistently. (Level AA)
The guideline requires that functional components (elements) that appear repeatedly in a set of web pages must have the same name/label. This helps Assistive aid users who heavily rely on these functional elements for quick navigation & understanding the purpose of a particular widget.
For example, if the “search button ” is labelled as either “find or go” in a web page while it is being labelled as “search” on all other pages, then it fails this checkpoint. This checkpoint applies to non-text content, icons and images that appear repeatedly & serve as labels too. In these cases, the alternative text for such labels must be consistent.
Besides being useful to assistive aid users, providing consistent visual non-textual labels for the repeated components reduces the cognitive load of users with cognitive disabilities who learn the repetitive functions of such components. For them, relearning every time when introducing new labels or alternative texts would be difficult.