ChatGPT is an app created by a for-profit company called OpenAI. It was initially free but now has a subscription component. Other AI tools are Google Bard, Microsoft Bing AI and many more. Since there are many ways to use ChatGPT and other tools -- the answer on whether using it is cheating is it DEPENDS.
Although there are not (yet) new policies about its use per se -- using (e.g. copy/paste) texts or code that is created by ChatGPT, for example, is covered under the CSUSB's Academic Dishonesty Policy and Procedures.
Plagiarism is defined in the Conduct Code as Plagiarism, "representing the words, creative work, or ideas of another person as one’s own without providing proper documentation of source." Some students might point out that "words" created by a tool like ChatGPT aren't a "person" -- these arguments miss the intent of the policy. The bottom line is YOUR INSTRUCTOR will determine whether it is a violation of academic dishonesty. If you aren't sure, ASK YOUR INSTRUCTOR for clarity.
One main way users interact with ChatGPT is to ask it a question, or give it a prompt and receive a quick answer.
How do they work?
Unlike a search engine, which searches and then gives results using information already created -- Large Language Models (LLMs) are making "new" content predicting the word most likely to come next (e.g. based on HUGE dataset -- publicly available Internet sites (which includes racist, conspiracy sites, etc.) as of ~2022). They are designed to model human language and use mathematical models to predict what the next word is most likely to be based on what you you are asking for. Keep in mind -- they don't think. They do NOT understand, read, choose or give you the "best information." Sometimes it might feel or seem like it but it is but this isn't how the technology works.
Prompts are the things you write into the tool to try to get it to do what you want. Better prompts can help you to try to get better outputs. These tools need very specific instructions, and they need you to verify/critically evaluate the information or output they give you. Learn more about prompts or a course like Prompt Engineering for Chat GPT.