Wallets and balances
A wallet in SavingStat is an account or a pile of cash with its own balance and one currency. What it holds, and what featuring and archiving actually do.
What a wallet is
A wallet in SavingStat is a place money sits: a current account, a card, the notes in a drawer. It has a name you choose, a balance, and one currency.
Every transaction names the wallet it moved through, and that wallet's balance moves with it. Drafts are the exception: a row that arrived from an import leaves every balance untouched until you publish it, which is why a messy import is safe to leave half-sorted.
One currency per wallet
The currency belongs to the wallet. A euro account and a dollar account are two wallets, each holding its own currency, and you choose that currency when you create the wallet.
Your account settings also hold a currency, but it does a different job: it is the currency your totals and charts are reported in. The settings currency does not decide what any wallet holds, and nothing forces your wallets to agree with it or with each other.
The settings currency does not preselect one either: the Add Wallet form opens on USD whatever your settings say, so a euro account needs the currency field changed before you save it. Getting it wrong is not fatal, since the edit form carries the same field, but every amount already recorded against the wallet is read in whatever currency the wallet says.
Your default wallet and archived wallets
One wallet can be marked featured, and only one. Marking a wallet featured clears the flag on every other wallet you own, so this is a single default rather than a shortlist of favourites.
Featuring does less than the name suggests. It does not move the wallet up the list: your wallets are ordered by a position you set by dragging them, and that order ignores the featured flag entirely. What a featured wallet gets you is a pre-filled field: the add-transaction form opens on it, with its currency already selected, so the wallet you reach for most is one less thing to pick.
Archiving is for a wallet you have stopped using. An archived wallet disappears from your wallet list and from the wallet picker on new transactions, but everything it already recorded stays exactly where it is. Deleting is the other option, and SavingStat refuses it outright while any transaction still points at the wallet. Archive when there is history you want to keep.