This may sound simple, but to people (like myself) coming from Bitcoin, its not immediately clear what a "Ledger" is. Does it equate with "The blockchain" or the "block"?
The Stellar documents are quite unclear. For example:
A ledger represents the state of the Stellar universe at a given point in time. It contains the list of all the accounts and balances, all the orders in the distributed exchange, and any other data that persists.
this sounds like the Ledger is a blockchain, since it contains all the data. but later on the same page:
Every ledger has a ledger header. This header has references to the actual data within the ledger as well as a reference to the previous ledger.
so every ledger has a previous ledger? that sounds like a block.
help me out here - how should I think of Ledger? what is it?