What does the Roman numeral 'V' in the Sun's stellar classification (G2V) specifically signify?

Answer

It resides on the main sequence

The Roman numeral 'V' in G2V signifies that the star resides on the main sequence, meaning it is actively fusing hydrogen in its core.

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