Is the following statement about workflow step types and their usage true?

Yes, the statement is true. When editing a step in the Business Process Editor in SailPoint IdentityIQ, the available step actions are Script, Rule, Subprocess, and Call Method. These actions allow for various types of logic and processing to be embedded within workflows. Each of these actions serves different purposes:

Script: Executes a Beanshell script.

Rule: Calls an existing IdentityIQ rule.

Subprocess: Invokes another workflow as a subprocess.

Call Method: Invokes a method on a specified object.

SailPoint IdentityIQ Business Process Editor Guide

SailPoint IdentityIQ Administration Guide (Section on Workflow Management)