Lineage uses a UTXO model: a transaction spends one or more previous outputs and creates new outputs that the next spend can refer to. There is no global “account balance” in the contract layer — balances are a view over unspent outputs.
Inputs and outputs
Each input points at a previous transaction hash and output index and carries a script that proves you may spend that coin. Each output states how much value is locked and under which script (e.g. pay-to-pubkey-hash style).
Versioning and metadata
Transactions carry a version and optional application-specific data (e.g. DRUID or item metadata) that higher layers can interpret. Your wallet or index should only rely on what your release’s schema guarantees.
HTTP API
Creating and querying transactions is covered under the Mempool API, especially create_transactions and address balance routes.