Although many people consider these terms to be the same, nevertheless, they are completely unrelated. Everything hanging on a flagpole or waving at the stadium is thought to be a flag. At least this comes in mind when anyone hears this term. However, there is a difference between flags and banners, and it is explained by the vexillology in greater details. It explains the exact difference between flags and banners.
In this explanation, it turns out that most flags that we see today are the flags. They are characterized by the fact that they are always attached to the flagpole indirectly, for example with the help of the rope. Thus, a flag can be replaced or changed very easy. That is why the flags are usually used at the political events, as at the state receptions.
On the contrary, a banner is attached directly to the flagpole. The best example of a banner can be found at the stadium, where fans are cheering for their teams waving corresponding flags. These banners carry their name because they are attached directly to the wooden stick. According to the definition of Vexillology, a banner is a painted cloth with symbols, lettering or other characters and, of course, can be also printed at present.
Must everyone know exactly the difference between a flag and a banner? Probably, it is not so important for many people in what way it is attached.