The "start" node is the only one that is a part of every single workflow. It's the origin of the audience that enters the flow.
Once you open the set up options for the node, you have to select a limitation for the contacts that will be part of the audience:
If we select "All my list" we're indicating that all the contacts that are part of our data base will be susceptible to be a part of the workflow or trigger the rest of the nodes.
Within that list, you can also select different segments by default, like "Contacts with email", "Contacts without email", "Only with mobile phone" or "Only with push subscriptions".
It's also possible to select as an audience a segment of contacts that was previously created by us:
If we check "All existing", the workflow will be executed only for the contacts that existed in Connectif at the moment of activation.
If we check "All new ones", the workflow will be executed only for the contacts that are created after the activation of this flow.
Finally, if we check "All existing and new", the workflow will gather every contact. It will use the existing ones and it can also include the ones created after the activation.
To set up the correct audience for each workflow, according to the goal, it's essential to carefully choose the limitation and the data source at this stage.