Oysters that are shucked, cooked, and packed in oil, brine, or a sauce. Some are smoked first, others are not. Either way they are ready to eat with no preparation.

No, and they are not trying to be. Canning firms the texture and concentrates the flavor. A raw oyster is about brine and freshness. A tinned one is about depth and salt.

On crackers or toast with lemon and hot sauce, or as part of a board with pickles and butter. They also fold well into dips, eggs, and potato dishes.

Not before opening. Unopened tins are shelf stable for years. After opening, move any leftovers to a covered container in the fridge and eat them within a couple of days.

It varies by producer. Pacific oysters are common in tins from the US West Coast, while European producers use local varieties. The species affects size and salinity more than anything else.