Oracle Workflow tables

WF_ACTIVITIES table stores the definition of an activity. Activities can
be processes, notifications, functions or folders. A process activity is a
modelled workflow process, which can be included as an activity in
other processes to represent a sub–process. A notification activity sends
a message to a performer. A functions activity performs an automated
function that is written as a PL/SQL stored procedure. A folder activity
is not part of a process, it provides a means of grouping activities.

WF_ITEMS is the runtime table for workflow processes. Each row
defines one work item within the system.

WF_ITEM_ATTRIBUTES table stores definitions of attributes
associated with a process. Each row includes the sequence in which the
attribute is used as well as the format of the attribute data.

WF_NOTIFICATIONS holds the runtime information about a specific
instance of a sent message. A new row is created in the table each time a
message is sent.