Any technology which gives an answer within milliseconds doesn't freeze and is fault safe.
What is Real Time Technology?
To get a better answer you should specify what subset of technology you want to know about. A real time OS has different requirements from real time rendering. Realtime is also often used as a marketing buzzword for things that don't need it.
For example, computers are already many orders of magnitude faster than retinas, so displaying a 60fps animation is really easy.The real-time technology refers to technology that permits a user to receive data amid the real-time that a physical procedure happens, known as real-time. Real-time is measured in milliseconds or microseconds. While RTT is utilized for advanced entertainment purposes