My understanding from my experience, ie my limited opinion and regional culture:
-bread is a base product from flour/salt/water and added yeast (also works with naturally occurring yeast, but longer, more difficult,,more risks)
-Comes in many sizes and shapes for many uses/occasions and also regional customs
-uses many types of flours and mixes.
Then you have special breads: seeds, or color of the flour. Usually the more refined the flour, the whiter and less tasty the bread.

And then you have variations with spices, bits of meat and many more variations coming with bread composed names or totally dedicated names

As for melon pan, sorry but this is a cake... or a variation of one,