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I exported my labels with that option and I also made a regular backup before, but I wonder if there is any difference and what else is contained in regular backup file (except labels)?
Maybe it is transactions, saved contacts and something else, but I couldn't find any information on electrum website.
It's exclusively for labels in 'History' and 'Addresses' tab.
IMO, it's for uses who want to restore their labels to a watch-only copy or to another instance of their wallet.
The "
regular backup" (
File->Save backup) is a complete copy of the wallet file, thus contains all wallet info including contacts.