Transaction models

All or nothing. A transaction needs to have all parts to succeed, otherwise it will fail. Example: Bank transfer (credit/debit)

A transaction needs to transition from one valid state to another.

Transactions don't interfere with each other

Transactions are stored and are durable (resistant to crashes)

Operations will be performed (read/write) but there are no guarantees about consistency.

Consistency enforcement is the responsibility of the application. The database won't check or enforce this.

Reads will become consistent at one point but not necessarily immediately.