Which of the following is used to implement workflows in Sitecore?

The implementation of workflows in Sitecore is fundamentally based on the concept of workflows themselves. Workflows in Sitecore define a sequence of steps and actions that content items must go through before being published or made live, effectively governing the content approval process. They provide a framework for controlling who can edit an item and when, which is vital for ensuring content quality and adherence to organizational policies.

Workflows consist of various states and roles, allowing different users or teams to contribute at different stages. Each state in a workflow can have associated commands that dictate specific operations to be executed based on the state of the content, but the overarching structure and management of these processes come from the workflow itself.

In contrast, while items represent the content within Sitecore's content tree, rules are conditions that can be applied within workflows or for content delivery preferences, and commands are actions that can be performed in response to state changes, neither of these elements are responsible for the overall orchestration of the workflow system. Therefore, the focus on workflows as the primary mechanism for implementing these processes makes them the correct answer to the question.