Over the last two decades, semantic theory has been marked by a continuing shift from a static view of meaning to a dynamic one. The increasing interest in extending semantic analysis from isolated sentences to larger units of discourse has fostered the intensive study of anaphora and coreference, and this has engendered a shift from viewing meaning as truth conditions to viewing it as the potential to change the "informational context".

The terms topic and focus are used by many theoreticians, but they often mean different things. In the most usual informal sense, topic is what an utterance is about (as contrasted to comment), and focus is what is emphasized in the utterance (as contrasted to background). Let us consider how this intuition can be sharpened.