i did not under stand how seams work
If you have a box and you to flatten it. But still in one piece of cardboard. No, lose parts.
Then you need a scissor (or knife), to separate some of the parts. But still no loose parts.
The cuts are the seams in Blender. It is how you split the box.
A box has six sides, so the most simple way is to cut them up into six parts.
But six loose parts is not an optional solution for Blender and painted textures.
By Adding seams you tell Blender where to cut.
Seams can be visible, so most designers make them at places where they can not be seen (backside).
Do you understand paper cut out models? They are in effect a form of UV map. The seams are the edges of the sections that need cutting out separately and then joined up to other pieces. Making a 3d card model from a flat set of parts.
so same thing as deleting in the 3D viewprt put in the uv unwrapping section and not deleting anyting in the 3d veiwport