I thought I wouldn't but I'm getting really, really confused with the naming and branding of what Gemini is a model and which is a product. Advanced, Pro, Ultra

I thought I wouldn't but I'm getting really, really confused with the naming and branding of what Gemini is a model and which is a product. Advanced, Pro, Ultra, seemingly Pro is getting better than Ultra? And Advanced is the product using the Ultra underlying model? Ugh, my brain.