A chatbot is a computer program that simulates human conversation through voice commands or text chats or both. Chatbot, short for chatterbot, is an Artificial Intelligence (AI) feature that can be embedded and used through any major messaging applications. There are a number of synonyms for chatbot, including "talkbot," "bot," "IM bot," "interactive agent" or "artificial conversation entity."
For example, say you want to purchase a pair of shoes online from Nordstrom. You would have to browse their site and look around until you find the pair you wanted. Then you would add the pair to your cart to go through the motions of checking out. But in the case Nordstrom had a conversational bot, you would simply tell the bot what you’re looking for and get an instant answer. You would be able to search within an interface that actually learns what you like, even when you can’t coherently articulate it. And in the not-so-distant future, we’ll even have similar experiences when we visit the retail stores.
As AOL's David Shingy writes in Adweek, "The challenge [with chatbots] will be thinking about creative from a whole different view: Can we have creative that scales? That customizes itself? We find ourselves hurtling toward another handoff from man to machine -- what larger system of creative or complex storytelling structure can I design such that a machine can use it appropriately and effectively?"
You can structure these modules to flow in any way you like, ranging from free form to sequential. The Bot Framework SDK provides several libraries that allows you to construct any conversational flow your bot needs. For example, the prompts library allows you to ask users for input, the waterfall library allows you to define a sequence of question/answer pair, the dialog control library allows you to modularized your conversational flow logic, etc. All of these libraries are tied together through a dialogs object. Let's take a closer look at how modules are implemented as dialogs to design and manage conversation flows and see how that flow is similar to the traditional application flow.
The classic historic early chatbots are ELIZA (1966) and PARRY (1972).[10][11][12][13] More recent notable programs include A.L.I.C.E., Jabberwacky and D.U.D.E (Agence Nationale de la Recherche and CNRS 2006). While ELIZA and PARRY were used exclusively to simulate typed conversation, many chatbots now include functional features such as games and web searching abilities. In 1984, a book called The Policeman's Beard is Half Constructed was published, allegedly written by the chatbot Racter (though the program as released would not have been capable of doing so).[14]
Customer service departments in all industries are increasing their use of chatbots, and we will see usage rise even higher in the next year as companies continue to pilot or launch their own versions of the rule-based digital assistant. What are chatbots? Forrester defines them as autonomous applications that help users complete tasks through conversation.   […]
Users want to ask questions in their own language, and have bots help them. A statement that sounds as straight-forward as “My login isn’t working! I haven’t been able to log into your on-line billing system” might sound straight forward to us, but to a bot, there’s a lot it needs to understand. Watson Conversation Services has learned from Wikipedia, and along with its deep learning techniques, it’s able to work out what the user is asking.

[In] artificial intelligence ... machines are made to behave in wondrous ways, often sufficient to dazzle even the most experienced observer. But once a particular program is unmasked, once its inner workings are explained ... its magic crumbles away; it stands revealed as a mere collection of procedures ... The observer says to himself "I could have written that". With that thought he moves the program in question from the shelf marked "intelligent", to that reserved for curios ... The object of this paper is to cause just such a re-evaluation of the program about to be "explained". Few programs ever needed it more.[8]