Library Flows
Library triggered Flows act as a sub-flow that can be called from other Flows. This is very useful to help segregate your flows, especially those that are to be re-used within several other Flows.
Here is an example of a Happy Birthday Library helper. The below library Flow takes a a user's birthdate (date) as input and checks if the day/month falls on the current day. It will return true if it's a match or false otherwise.
One the above Library Flow is enabled, we can then find it under the Team Library stages in any other flow and can use it like any other stage as follows:
The above would trigger on a user login and check if it's the user's Birthday today by using our Library Flow.