It's a distributed database for tracking accounts and transfers of amounts of "thing"s between accounts (currency is one example of a "thing"). You might also be interested in our FAQ on why someone would want this [1].
[0] https://github.com/tigerbeetledb/tigerbeetle#quickstart
[1] https://docs.tigerbeetle.com/FAQ/#why-would-i-want-a-dedicat...
And you can model external accounts that have their own confirmation process using our two-phase transfer support.
Yes, exactly. You can think of TigerBeetle as your internal ledger database, where perhaps in the past you might have had to DIY your own ledger with 10 KLOC around SQL.
And to add to what Phil said, you can also use TigerBeetle to track transactions with other parties, since we validate all user data in the transaction—there are only a handful of fields when it comes to double-entry and two-phase transfers between entities running different tech stacks.
The TigerBeetle account/transfer format is meant to be simple to parse, and if you can find user data that would break our state machine, then it's a bug.
Happy to answer more questions!