As IBM elaborates: “The front-end app you develop will interact with an AI application. That AI application — usually a hosted service — is the component that interprets user data, directs the flow of the conversation and gathers the information needed for responses. You can then implement the business logic and any other components needed to enable conversations and deliver results.”
The most widely used anti-bot technique is the use of CAPTCHA, which is a form of Turing test used to distinguish between a human user and a less-sophisticated AI-powered bot, by the use of graphically-encoded human-readable text. Examples of providers include Recaptcha, and commercial companies such as Minteye, Solve Media, and NuCaptcha. Captchas, however, are not foolproof in preventing bots as they can often be circumvented by computer character recognition, security holes, and even by outsourcing captcha solving to cheap laborers.
Facebook has jumped fully on the conversational commerce bandwagon and is betting big that it can turn its popular Messenger app into a business messaging powerhouse. The company first integrated peer-to-peer payments into Messenger in 2015, and then launched a full chatbot API so businesses can create interactions for customers to occur within the Facebook Messenger app. You can order flowers from 1–800-Flowers, browse the latest fashion and make purchases from Spring, and order an Uber, all from within a Messenger chat.
Your bot can use other AI services to further enrich the user experience. The Cognitive Services suite of pre-built AI services (which includes LUIS and QnA Maker) has services for vision, speech, language, search, and location. You can quickly add functionality such as language translation, spell checking, sentiment analysis, OCR, location awareness, and content moderation. These services can be wired up as middleware modules in your bot to interact more naturally and intelligently with the user.
Artificial neural networks, invented in the 1940’s, are a way of calculating an output from an input (a classification) using weighted connections (“synapses”) that are calculated from repeated iterations through training data. Each pass through the training data alters the weights such that the neural network produces the output with greater “accuracy” (lower error rate).

Web site: From Russia With Love. PDF. 2007-12-09. Psychologist and Scientific American: Mind contributing editor Robert Epstein reports how he was initially fooled by a chatterbot posing as an attractive girl in a personal ad he answered on a dating website. In the ad, the girl portrayed herself as being in Southern California and then soon revealed, in poor English, that she was actually in Russia. He became suspicious after a couple of months of email exchanges, sent her an email test of gibberish, and she still replied in general terms. The dating website is not named. Scientific American: Mind, October–November 2007, page 16–17, "From Russia With Love: How I got fooled (and somewhat humiliated) by a computer". Also available online.
Interface designers have come to appreciate that humans' readiness to interpret computer output as genuinely conversational—even when it is actually based on rather simple pattern-matching—can be exploited for useful purposes. Most people prefer to engage with programs that are human-like, and this gives chatbot-style techniques a potentially useful role in interactive systems that need to elicit information from users, as long as that information is relatively straightforward and falls into predictable categories. Thus, for example, online help systems can usefully employ chatbot techniques to identify the area of help that users require, potentially providing a "friendlier" interface than a more formal search or menu system. This sort of usage holds the prospect of moving chatbot technology from Weizenbaum's "shelf ... reserved for curios" to that marked "genuinely useful computational methods".