What does the 'Copy data Components' block actually do

[Copy data components of ___ (if it has any) onto ___]

I've been trying to figure out how to actually make use of this block. I thought it would transfer all the nbt data of an item to another but it seems like it literally just copy pastes an item and I can't seem to find anyone talking about it.

I do noticed that it changed the tooltip name of the item but that's about it, it still functions as the same item.