Interfaces place demands on limited human attention and memory.

Recall requires a person to retrieve information without seeing it, such as remembering an exact command name. Recognition lets the user identify the needed option from visible choices.

Recognition is usually easier, but exposing every possible choice at once can create clutter and slow selection. Good interfaces keep frequently needed information visible while grouping or progressively revealing less common options.

Users also maintain task state in memory: what they were doing, which step is complete and what remains. Interruptions or long workflows make hidden state especially costly.

Labels, previews, history, breadcrumbs and persistent progress can externalize information that users would otherwise need to remember.

Reducing cognitive load does not mean removing all complexity. It means letting the interface carry information that the system already knows instead of requiring the user to reconstruct it mentally.