Bard uses a smaller model currently, which was announced before release.
> We’re releasing it initially with our lightweight model version of LaMDA. This much smaller model requires significantly less computing power, enabling us to scale to more users, allowing for more feedback. [1]
> Bard is powered by a research large language model (LLM), specifically a lightweight and optimized version of LaMDA, and will be updated with newer, more capable models over time. [2]
[1] https://blog.google/technology/ai/bard-google-ai-search-upda...