100% GPL licence theme

I bought a Cripton theme 2 years ago and already have it on one site. I’m doing now another site, and this theme is pretty good, but when I came to it on Theme Forest I saw:

  • Not included: DeoThemes does not support this item
    This item is licensed 100% GPL.

I saw this first time on Theme Forest, and after Googleing I saw that 100% GPL means that I can use this theme on as many sites as I want?

Is this correct, because I’m doing another site and then I don’t need to buy the theme again…

This theme: https://themeforest.net/item/cripton-cryptocurrency-magazine-wordpress-theme/22522995/

Thank you.