Each [ledger version](ledgers.html)'s state data is a set of **ledger objects**, sometimes called _ledger entries_, which collectively represent all settings, balances, and relationships at a given point in time. To store or retrieve an object in the state data, the protocol uses that object's unique **[Ledger Object ID](ledger-object-ids.html)**.

In the [peer protocol](peer-protocol.html), ledger objects have a [canonical binary format](serialization.html). In `rippled` APIs, ledger objects are represented as JSON objects.

A ledger object's data fields depend on the type of object; the XRP Ledger supports the following types: