Autolaunched subflows for reusable logic
Key Takeaway
Put a common task in one small Autolaunched flow, activate it, and call it from other flows with a Subflow element.
A subflow is a flow that another flow runs as one of its steps, using a Subflow element. Admins often build small Autolaunched flows that each do one common task, then call them from many other flows. The shared logic lives in one place, so admins don't rebuild it in every flow.
Parent flows and child flows
The Subflow element runs another active flow in the org. The flow that contains the Subflow element is the parent flow. The flow it runs is the child flow, also called the referenced flow.
Salesforce recommends creating smaller flows that perform common tasks and calling them wherever they are needed.
For example, you can build utility flows that capture address and credit card information or authorize a credit card purchase amount. You can then call these utility flows from multiple product-ordering flows.