Democracy International uses the terms of direct democracy - citizens' initiative, obligatory referendum and plebiscite - in the following way:
A procedure and a political right that allows a given number of citizens to put their own proposal on the political agenda. The procedure is initiated by a prescribed number of eligible voters that leads to a referendum in its second step.
This procedure is triggered automatically by law (usually the constitution) and requires that certain issues must be put before the voters for approval or rejection.
A popular vote procedure whose use lies exclusively within the control of an authority. In this form the author of the proposal and the initiator of the procedure are the same. Direct democracy in terms of a citizen-initiated or obligatory referendum is not concerned.