• Data do not flow directly between processes – the
data that enter a process will come either from a
source or from a datastore, they cannot exist in a
vacuum!
• Data do not flow directly between datastores – there
must be an intervening process that takes the input
data and converts them into a new form and outputs
them to either a datastore or a sink.
• Data do not flow directly from a datastore to a sink,
or from a source to a datastore – there must be an
intervening process.