In the late twentieth century ledgers moved from analog to digital ledgers. For example, in the 1970s the Australian passport ledger was digitised and centralised. A database allows for more complex distribution, calculation, analysis and tracking. A database is computable and searchable.
But a database still relies on trust; a digitised ledger is only as reliable as the organisation that maintains it (and the individuals they employ). It is this problem that the blockchain solves. The blockchain is a distributed ledgers that does not rely on a trusted central authority to maintain and validate the ledger.