There are many definitions of what exactly constitutes "real time". I find it is a very relative thing, depending on who you talk to. When asked, many will respond with push notifications as an example. Others immediately think chat and messaging. If you are talking to developers they will reference specific technology like XMPP, Jabber, and WebSockets.
Real time is relative. It is relative to the situation, and to those involved. I'd say real time also isn't good by default, in all situations. The need for real time might change or evolve, and mean different things in different industries. All of this variance really opens up the concept for a lot of manipulation and abuse.
I feel like those who are wielding real time often speak of the benefits to us when in reality it is about real time in service of what they desire. They want a real time channel to you so they can push to you anytime, and get the desired action they are looking for (ie. click, view, purchase). In this environment, the concept of real time quickly becomes just noise, distraction, and many other negative things--rendering real time to just often being a pretty bad idea.