[hargup]

Gemma is their open-source series of models. Gemini is the propertierary ones. Gemini models are bigger and better. But Gemma are pretty good too.

[tpm]

open-weights, not open-source (sorry to be that one but open source in this case would mean you can build it yourself from provided "source", which you can't, because it's not provided)

[mrob]

And even "open-weights" is generous, as they're released under a proprietary license with usage restrictions, not an open-source license.