All real time system are online system but converse is not true. Justify?

All real-time systems are online systems because they operate continuously and respond to inputs in real-time, often requiring immediate processing and feedback. However, not all online systems are real-time; some online systems may not have strict timing constraints and can tolerate delays in processing. For example, a web application that handles user requests intermittently may be online but does not require real-time processing. In contrast, a real-time system, such as an air traffic control system, must deliver timely responses to ensure safety and efficiency.