I ask the question because when I look in at the outliner after adding a modifier to an object I see:
wrench and under the wrench I see the name of the modifier.
I do not believe modifiers are data-blocks. and if that is true, what is being attached to the object?
I guess it could be the children of the wrench could be technically called "automatic operations "?
any hint on what Modifier are and how they can be Non-Destructive would great help.
Something like that what you already said. Usually there is some data which descriped the geometry ( → objects). Modifiers are just coded internal procedures to changes those data in a specific way ( → tools/wrench) . So they are nothing else as additional data.