How is direct democracy practiced in california?

The three tools are referendums, recalls, and initiatives (called propositions once their on a ballot). Each one gives more power to the people in a specific way, with initiatives carrying the most power of all.

Referendum is a right reserved by the people to approve or reject an act of legislature or legislation referred by them before it becomes operative as a law.

Recall is a right to which by popular vote a public official may be removed from office before the end of their term of office.

Initiative is a process of participatory democracy (type of direct democracy) that empowers the people to propose legislation and to enact or reject laws at the polls independent of the legislative branch.