The MBTA's long-awaited South Coast commuter rail line​ finally began service Monday, connecting southeastern Massachusetts with Boston.

The MBTA’s South Coast rail begins service Monday, shuttling riders from Boston’s South Station to Taunton, Fall River and New Bedford. Those three communities were the only “major cities” within 50 miles of Boston that were not serviced by the Commuter Rail — until Monday.

How much does it cost? What's the schedule? And where does it go exactly? Here are the basics to know about the MBTA's new South Coast Rail service.