Learn in the textbookPerformance Evaluation
DefinitionResponse time (レスポンスタイム) is the time from when a user finishes entering a processing request until the system's first response begins to come back.
ExplanationTiming starts when input ends, so the time spent on the input itself is not included. Shorter values mean less waiting for the user, which matters most in online processing (オンライン処理), where people work interactively with the screen.
AnalogyIt is like the gap between finishing your request at a service counter and the clerk's first words in reply. That is counted separately from the time needed to finish the whole procedure.