Preventive conservation first studies the environment of an object or collection; in this respect, it is an indirect action. A broader definition and practice, however, include direct action on the object or collection once the damage has been identified - we then refer to "curative" conservation, which consists of taking action to prevent further damage : nitrogen anoxia treatment for pest eradication, for example, or strengthening an item which threatens to break or tear.
Yet preventive conservation (even including curative conservation) should never be confused with restoration: the aim of the latter is to restore an object to its pre-damage state, to make it comprehensible (by restoring its "normal" appearance), or to recover its aesthetic qualities.
It should be noted, however, that current restoration practices in France involve minimum intervention, and traces of wear (the action of time) tend to be preserved as far as possible as they testify to the object’s history (even though they may be unaesthetic). Restoration deontology is therefore based on three principles: readability (we must be able to identify what the restorer has done), reversibility (we must be able to un-do what has been done), and stability (the restoration work must not ultimately threaten the preservation of the object).