Chat GPT, whose interface hasn't changed much since the beginning, but due to the additional models, it now produces upgraded and different content. Also available is Claude AI. Now, Claude AI has traditionally been used for writing tasks. However, it has now upgraded its model and also provides upgraded content. Lesser known but just as powerful is perplexity AI, which individuals use for research but can also be used as a chatbot. You may also use Google Gemini. Gemini has special features both in the chatbot and outside of specialty projects such as notebook LM. And finally, another source is now meta AI, whose model does not yet rely on a pricing model but whose core is open source. Here's a video course that will compare different ways each chatbot reacts to similar prompts, which could be used to help you to accomplish different purposes.