Initiative, referendum, and recall.
The initiative is the process that enables citizens to bypass their state legislature by placing proposed statutes , and in some states, constitutional amendments.
Referendum is a measure that appears on the ballot.There is a legislative referendum where the legislature refers a measure to the voters for their approval, and then there is a popular referendum, where the measure appears on the ballot as a result of voter petition drive.
Recall is a procedure that allows citizens to remove and replace a public official before the end of a term of office.
