Aging and Restoration of Historic Buildings

The restoration of cultural relics is a very common word, but what exactly is the restoration of cultural relics?

Is it a good way to "restore the old as before" for cultural relics?

How do professional cultural relic building restorers carry out restoration work?

In the new book, Lu Zeqiang, a French cultural heritage architect, introduces the restoration work of cultural relics buildings, introduces the restoration methods and guidelines in simple terms, and also knows what the restoration of cultural relics does.