This connector type is commonly used to connect a battery, stepper motors or endstops in 3dprinters.
Offers more secure connection than generic du-Pont style connector.
Pigtail spares you need to crimp lead on wires yourself, that requires both specialised tool and a practice.
10cm should fit most wire to board needs for a small project.
Pitch: 2.54 - fit spacing of prototype boards.