Data store symbol
A data store is used in a DFD to represent data that the
system stores because one or more processes need to use
the data at a later time.
The symbol of a data store is a flat rectangle that is open
on the right side and closed on the left side.
The name of the data store appears between the lines
and identifies the data it contains.
A data store name is a plural name consisting of a noun
and adjectives. E.g. STUDENTS, ACCOUNTS
RECEIVABLE, PRODUCTS, DAILY PAYMENTS,
PURCHASE ORDERS.