ChatBots are programs that allow businesses to provide automated customer support, guidance, and experiences through messaging platforms like Facebook Messenger. They help businesses by providing conversational responses without delay, securely communicating with customers, and reducing the workload for customer support teams. While chatbots have limitations like being less flexible than human agents and sometimes requiring human expertise, they are well-suited for applications like product discovery, ordering, customer support, banking, and news. Businesses should consider building a chatbot if they deal with regular ordering, want to automate FAQs, or have a large social media following.