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Workflow engine: Executes workflows (instances of a workflow definition), recording transactions and maintaining the state of each workflow that is in progress, including associated data and files.
Permissions, roles, groups, and identities: Determine how end users are authorized to participate in workflows, how administrators are authorized to manage the workflow solution, and how the workflow engine is authorized to interact with other systems. Authorization may be local to the workflow system or managed separately from the workflow system and other systems participating in the workflow solution (enterprise authorization).
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