According to Richard Wallace, chatbots development faced three phases over the past 60 years. In the beginning, chatbot only simulated human-human conversations, using canned responses based on keywords, and it had almost no intelligence. Second phase of development was strictly associated with the expansion of Internet, thanks to which a chatbot was widely accessed and chatted with thousands of users. Then, the first commercial chatbot developers appeared. The third wave of chatbots development is combined with advanced technologies such as natural language processing, speech synthesis and real-time rendering videos. It comprises of chatbot appearing within web pages, instant messaging, and virtual worlds.
The “web-based” solution, which runs on a remote server, is generally able to be reached by the general public through a web page. It constitutes a web page with a chatbot embedded in it, and a text form is the sole interface between the user (you) and the chatbot. Any “upgrades” or improvements to the interface are solely the option and responsibility of the botmaster.
Derived from “chat robot”, "chatbots" allow for highly engaging, conversational experiences, through voice and text, that can be customized and used on mobile devices, web browsers, and on popular chat platforms such as Facebook Messenger, or Slack. With the advent of deep learning technologies such as text-to-speech, automatic speech recognition, and natural language processing, chatbots that simulate human conversation and dialogue can now be found in call center and customer service workflows, DevOps management, and as personal assistants.
One pertinent field of AI research is natural language processing. Usually, weak AI fields employ specialized software or programming languages created specifically for the narrow function required. For example, A.L.I.C.E. uses a markup language called AIML, which is specific to its function as a conversational agent, and has since been adopted by various other developers of, so called, Alicebots. Nevertheless, A.L.I.C.E. is still purely based on pattern matching techniques without any reasoning capabilities, the same technique ELIZA was using back in 1966. This is not strong AI, which would require sapience and logical reasoning abilities.
[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.
Several studies accomplished by analytics agencies such as Juniper or Gartner  report significant reduction of cost of customer services, leading to billions of dollars of economy in the next 10 years. Gartner predicts an integration by 2020 of chatbots in at least 85% of all client's applications to customer service. Juniper's study announces an impressive amount of $8 billion retained annually by 2022 due to the use of chatbots.
Chat bot, chatbot or chatterbot, can be found on screens and in the virtual worlds, but also in the real world, for example holographically projected or as physical talking and responding puppet, toy or robot. Often, chat bot appears online and in instant messenger programs such as Windows Live Messenger, AOL Instant Messenger or Google Talk, where a chat bot is part of the buddy, contact or follow list of the human user. Chat bot appears on many other platforms as well, such as social networks (e.g. Facebook), virtual worlds (e.g. Second Life) or mobile devices (e.g. iPhone).
The term "ChatterBot" was originally coined by Michael Mauldin (creator of the first Verbot, Julia) in 1994 to describe these conversational programs. Today, most chatbots are accessed via virtual assistants such as Google Assistant and Amazon Alexa, via messaging apps such as Facebook Messenger or WeChat, or via individual organizations' apps and websites. Chatbots can be classified into usage categories such as conversational commerce (e-commerce via chat), analytics, communication, customer support, design, developer tools, education, entertainment, finance, food, games, health, HR, marketing, news, personal, productivity, shopping, social, sports, travel and utilities.