Why my Seeeduino Stalker has both a CR2032 battery holder and a JST battery connector?

The Seeeduino Stalker has a Master Switch, which turns off the device. But it also has a Real Time Clock (RTC) which needs power to run. To keep the RTC running when the Master Switch is set to off, you will need to insert 3V in the CR2032 battery holder pins, normally by inserting such battery in the slot.

The JST battery connector, in its turn, is one way of powering the whole board, others being using the Stalker as a shield, or powering it up through the UART connector.