Yes, you can add any number of sources to each of your pipelines.
Remember, pipelines allow you to use LeadSimple to track and follow up with multiple types of leads (Owners, Tenants, Buyers, Sellers, etc.) You can then set up multiple sources inside each pipeline to label the leads within that pipeline.
They can be auto-imported or non-auto-imported sources, and they can be different for each pipeline.
If the source is Enabled (Green), it means that leads have started being auto-imported from it.
If the source is Pending (Orange), it means that no leads have been auto-imported yet, even though the source may be set up correctly.
Learn more about how to add sources and set up auto-import here.