What is Google Bard?
Bard is Google's experimental, conversational, AI chat service. It is meant to function similarly to ChatGPT, with the biggest difference being that Google's service will pull its information from the web. 

When was Google Bard announced?
Bard was unveiled on February 6 in a statement from Google and Alphabet CEO Sundar Pichai. Even though Bard was an entirely new concept at the announcement, the AI chat service is powered by Google's Language Model for Dialogue Applications (LaMDA), which was unveiled two years ago. 

How does Google Bard work?
LaMDA was built on Transformer, Google's neural network architecture that it invented and open sourced in 2017. Interestingly, GPT-3, the language model ChatGPT functions on, was also built on Transformer, according to Google. 

Also: Google's Bard builds on controversial LaMDA bot that engineer called 'sentient' 

The initial version of Bard will utilize a lightweight model version of LaMDA, because it requires less computing power and can be scaled to more users, according to the release. In addition to LaMDA, Bard will draw on all the information from the web to provide responses. Pichai said pulling from the web would provide "fresh, high-quality responses."

https://www.zdnet.com/article/what-is-google-bard-heres-everything-you-need-to-know/