The Flow Component node allows you to start a Flow (Flow 1) from another Flow (Flow 2).
You can pass custom variables from the triggering Flow to the triggered Flow using the Start node. Keep in mind that when starting a Flow from the Flow Component node some of the Start variables in triggered flow will be empty:
This node is very similar to the Flow Starter node, the difference is that when a Flow is started from the Starter node, a new Flow Run is started. When a Flow is started from the **Component ** node, there is no new run but the nodes of the used flow are added to the triggering flow (like the Nested UI in UIs) as shown in this animation: