Definitions/Availability

From the Initiative and Referendum Almanac

Initiative

Direct Initiative – proposed by the people and goes directly to the ballot

Indirect Initiative – proposed by the people and is first submitted to the legislature for hearings and a vote before going on the ballot if not enacted by the legislature

Referendum

Legislative referendum – when the legislature places a question on the ballot (allstates have this)

Popular referendum – when people place legislation enacted by the legislature on the ballot for the people to accept or  reject (24 states have this, but not the same 24 that have Initiative — KY, MD, NM have popular referendum, but not
initiative — FL, IL, MS have initiative, but not popular referendum)

Constitutional Amendment Initiatives — 18 states have this

16 states have the direct initiative amendment process
2 have the indirect process

Statutory initiatives – 21 states have this

14 states have the direct initiative statutes process
9 have the indirect process (this adds up to 23, since two states allow both direct and indirect)…note: only five require the indirect process
24 states have Initiative, not all have both constitutional and statutory.