You made me laugh out loud.
Ok let me rephrase it.
By definition its bread. Plain simple white bread. You buy it and can toast it.
It is sould under the name of toast. Because well it is commonly toasted and eaten.
If you ask a german what toast is he will show you this:
View attachment 852142
(buttered toast)
White bread.
Now to why many germans don't consider this actual bread, even though it is by definition.
Well when we think about bread we think about sour dough bread, full wheat bread, dark bread, Komissbrot (even though nobody calls it that here) and so on. We are not that into white wheat breads. They are seen as unhealthy and associated with mass production (this does not include baguette and various other white bread types from italy).
Basically if a bread looks similar to this:
View attachment 852145
or this
View attachment 852146
Its conssidered real bread. Of course the personal preference also plays a role.
But overall white bread thats shaped like wonderbread is associated with unhealthy massproduced food.
Which doesn't mean that every white bread is considered Bad. Only the shape