What does the Roman numeral 'V' in the Sun's G2V classification signify?

Answer

Main-sequence star

The Roman numeral V indicates that the Sun is a main-sequence star. This is the longest phase in a star's life where hydrostatic equilibrium is maintained by balancing the outward pressure from fusion against the inward pull of gravity.

What does the Roman numeral 'V' in the Sun's G2V classification signify?
sunastronomystarcelestial body