Here's what that means:

* G-type: This refers to its spectral class, which is determined by its surface temperature. G-type stars are yellow-white in color, with a surface temperature of roughly 5,000-6,000 Kelvin.

* Main-sequence: This refers to the stage of a star's life where it is fusing hydrogen into helium in its core. The vast majority of stars spend most of their lives on the main sequence.

So, in short, our Sun is a pretty average, middle-aged star, in terms of its size, temperature, and lifespan.