A lot of people are immediately aware of the differences between real and fake. When you say fake, this is something that has not been verified. It can be very easy for some people to come up with something without the need to verify the facts.
Even you can create something out of thin air and try to make people believe that it is true. When you say real, this means that this is something that is genuine. This is something that is verified by the different facts that are available.
There are times when it will be hard to determine if something is real or fake based on the things that you will be said to you but always double-check your facts first just to be sure that you are not spreading something fake.