Conversational bots work in a similar way as an employee manning a customer care desk. When a customer asks for assistance, the conversational bot is the medium responding. If a customer asks the question, “What time does your store close on Friday?” the conversational bot would respond the same as a human would, based on the information available. “Our store closes at 5pm on Friday.”
Facebook Messenger chat bots are a way to communicate with the companies and services that you use directly through Messenger. The goal of chat bots is to minimize the time you would spend waiting on hold or sifting through automated phone menus. By using keywords and short phrases, you can get information and perform tasks all through the Messenger app. For example, you could use bots to purchase clothing, or check the weather by asking the bot questions. Bot selection is limited, but more are being added all the time. You can also interact with bots using the Facebook website.

There are a bunch of e-commerce stores taking advantage of chatbots as well. One example that I was playing with was from Fynd that enables you to ask for specific products and they'll display them to you directly within Messenger. What's more, Facebook even allows you to make payments via Messenger bots, opening up a whole world of possibility to e-commerce stores.
Think about the possibilities: all developers regardless of expertise in data science able to build conversational AI that can enrich and expand the reach of applications to audiences across a myriad of conversational channels. The app will be able to understand natural language, reason about content and take intelligent actions. Bringing intelligent agents to developers and organizations that do not have expertise in data science is disruptive to the way humans interact with computers in their daily life and the way enterprises run their businesses with their customers and employees.
A chatbot (also known as a spy, conversational bot, chatterbot, interactive agent, conversational interface, Conversational AI, talkbot or artificial spy entity) is a computer program or an artificial intelligence which conducts a conversation via auditory or textual methods.[1] Such programs are often designed to convincingly simulate how a human would behave as a conversational partner, thereby passing 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.