Open JKSV and you will meet save categories most players never think about: Account, System, BCAT, Device, Temporary, Cache and more. They are not labels for difficulty; they describe who owns the data and where it lives, and understanding them explains everything from why one game has a single island to why some data should never be casually restored. This guide explains each type in plain language. JKSV, which covers all of them, is on our download page. More platform guides sit on the comparisons hub.
Account save data: the familiar kind
Account save data is the per-user progress most people mean by ‘a save’. Each user profile on the console gets its own data for the game, which is why two players on one Switch can have separate campaigns. When you back up a game in JKSV for ordinary purposes — protecting progress, moving it to another console, editing it on PC — you are almost always working with Account saves. Back them up per user, label them clearly, and restores will put progress back under the same profile it came from.
System save data, by contrast, belongs to the console and its system software rather than to a player or a single game’s progress. It exists, JKSV can see it, and it should be treated with respect: restoring system data casually is how consoles develop strange behaviour. Back it up if you are being thorough; restore it only when you know exactly why.
BCAT and System BCAT: data delivered to games
BCAT data is content delivered to games over time, such as event distributions and dynamic content a title downloads rather than ships with. It is tied to the game but is not your progress in it. System BCAT is the system-level counterpart. For backup purposes, BCAT matters when a game’s delivered content is part of what you want to preserve or transfer, and it is one reason a complete JKSV backup captures more than a single ‘save file’ mental model suggests.
The practical rule is simple: when in doubt, include BCAT data in a full backup of a title you care about, because leaving it behind is a silent way to arrive at the new console with a slightly emptier game.
Device and shared data: one copy for the whole console
Device, or Device-Shared, save data belongs to the console as a whole rather than to any user. The famous example is Animal Crossing: New Horizons, where the island is a single Device save shared by every profile on that Switch, explored in our island backup guide. Backing up only your Account data and expecting the island to travel with it is a classic and heartbreaking mistake. Device saves are the ones to identify before any console move.
Temporary save data is working data the system creates for short-lived purposes, and Cache save data is storage a title uses as a cache, including the cache saves JKSV itself handles when listing titles quickly. Neither is where your progress lives. Knowing they exist stops two errors: panicking that a cache looks like a save, and restoring temporary data as if it were progress.
How to use this in JKSV
In practice: for a normal game, back up the Account save for each user who plays it. For a console move, include Device data for games that use it, and let a whole-system batch backup sweep up the rest so nothing is left to memory. For editing on PC, you want the Account save as an unpacked folder. For archiving, take everything JKSV offers for the title, BCAT included, because storage is cheap and missing data is not recoverable later.
JKSV’s full coverage of these types is a major reason it anchors our best Switch save managers shortlist. Learn the six labels once, and every backup decision after that becomes obvious. Related: how these local files compare with NSO cloud saves.