Simply, it allows you to have access to the internet regardless of how remote your location!
Technically, Very Small Aperture Terminal (VSAT) is a two-way satellite ground station or a stabilized maritime VSAT antenna with a dish antenna that is smaller than 3 meters. The majority of VSAT antennas range from 75 cm to 1.2 m. Data rates range from 4 kbit/s up to 4 Mbit/s; some upgraded modules can even reach a max downlink of up to 16 Mbit/s.
VSATs are used to transmit narrowband data (e.g., point-of-sale transactions using credit cards, or polling), or broadband data for the provision of satellite Internet access to remote locations.