The term Open Interfaces actually refers to table driven interfaces, where you put data in a table that sits between your external application and the Oracle module you are interfacing with.
The term API refers to stored procedure driven interfaces, where you call a stored procedure to perform an action within an Oracle Module, and the data from your external application is passed through the stored procedure’s parameters.
Historically, there were only table driven interfaces and they were called Open Interfaces. Later, stored procedures were added and were called APIs.
