A chatbot is a computer program which conducts a conversation via auditory or textual methods. Such programs are often designed to convincingly simulate how a human would behave as a conversational partner, although as of 2019, they are far short of being able to pass the Turing test. Chatbots are typically used in dialog systems for various practical purposes including customer service or information acquisition. Some chatbots use sophisticated natural language processing systems, but many simpler ones scan for keywords within the input, then pull a reply with the most matching keywords, or the most similar wording pattern, from a database.
Yes. Messenger bots are approved by Facebook before being made available inside the Messenger app so you can rest assured that they aren’t trying to steal your identity (or anything else). What’s more is a bot is tied to a Facebook page and a Facebook app making it all the more inconvenient to use for fraudulent activity. That said, don’t exchange private and/or personal information with a bot. Finally, because Messenger doesn’t support credit cards and purchasing just yet, anything you buy will likely be done via a browser with a bot aiding you so far as to place an order. If you want, you can always block a bot.