Gemini is a family of competent multimodal models developed at Google. Gemini was trained jointly across image, audio, video, and text data to build a model with solid generalist capabilities across modalities alongside cutting-edge understanding and reasoning performance in each respective domain.

Gemini is actually a family of AI models. It comes in three different models:

• Gemini Ultra, the flagship Gemini model
• Gemini Pro, a “lite” Gemini model
• Gemini Nano, which is distilled to run on mobile devices

Source: https://techcrunch.com/2023/12/06/googles-gemini-isnt-the-generative-ai-model-we-expected/