There are different approaches and tools that you can use to develop a chatbot. Depending on the use case you want to address, some chatbot technologies are more appropriate than others. In order to achieve the desired results, the combination of different AI forms such as natural language processing, machine learning and semantic understanding may be the best option.
“We believe that you don’t need to know how to program to build a bot, that’s what inspired us at Chatfuel a year ago when we started bot builder. We noticed bots becoming hyper-local, i.e. a bot for a soccer team to keep in touch with fans or a small art community bot. Bots are efficient and when you let anyone create them easily magic happens.” — Dmitrii Dumik, Founder of Chatfuel

In a traditional application, the user interface (UI) is a series of screens. A single app or website can use one or more screens as needed to exchange information with the user. Most applications start with a main screen where users initially land and provide navigation that leads to other screens for various functions like starting a new order, browsing products, or looking for help.
More and more businesses are choosing AI chatbots as part of their customer service team. There are several reasons for that. Chatbots can answer customers’ inquiries cheaply, quickly, in real-time. Another reason is the ease of installation of such chatbot: once you have a fine live chat app, it takes a couple of minutes to integrate a chatbot with it.
This means our questions must fit with the programming they have been given.  Using our weather bot as an example once more, the question ‘Will it rain tomorrow’ could be answered easily. However if the programming is not there, the question ‘Will I need a brolly tomorrow’ may cause the chatbot to respond with a ‘I am sorry, I didn’t understand the question’ type response.
Now, with the rise of website chatbots, this trend of two-way conversations can be taken to a whole new level. Conversational marketing can be done across many channels, such as over the phone or via SMS. However, an increasing number of companies are leveraging social media to drive their conversational marketing strategy to distinguish their brand and solidify their brand’s voice and values. When most people refer to conversational marketing, they’re talking about interactions started using chatbots and live chat – that move to personal conversations.
Chatbots are often used online and in messaging apps, but are also now included in many operating systems as intelligent virtual assistants, such as Siri for Apple products and Cortana for Windows. Dedicated chatbot appliances are also becoming increasingly common, such as Amazon's Alexa. These chatbots can perform a wide variety of functions based on user commands.
Developed to assist Nigerian students preparing for their secondary school exam, the University Tertiary Matriculation Examination (UTME), SimbiBot is a chatbot that uses past exam questions to help students prepare for a variety of subjects. It offers multiple choice quizzes to help students test their knowledge, shows them where they went wrong, and even offers tips and advice based on how well the student is progressing.
The classic historic early chatbots are ELIZA (1966) and PARRY (1972).[5] 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).[6]
ALICE – which stands for Artificial Linguistic Internet Computer Entity, an acronym that could have been lifted straight out of an episode of The X-Files – was developed and launched by creator Dr. Richard Wallace way back in the dark days of the early Internet in 1995. (As you can see in the image above, the website’s aesthetic remains virtually unchanged since that time, a powerful reminder of how far web design has come.) 
Next, identify the data sources that will enable the bot to interact intelligently with users. As mentioned earlier, these data sources could contain structured, semi-structured, or unstructured data sets. When you're getting started, a good approach is to make a one-off copy of the data to a central store, such as Cosmos DB or Azure Storage. As you progress, you should create an automated data ingestion pipeline to keep this data current. Options for an automated ingestion pipeline include Data Factory, Functions, and Logic Apps. Depending on the data stores and the schemas, you might use a combination of these approaches.

Designing for conversational interfaces represents a big shift in the way we are used to thinking about interaction. Chatbots have less signifiers and affordances than websites and apps – which means words have to work harder to deliver clarity, cohesion and utility for the user. It is a change of paradigm that requires designers to re-wire their brain, their deliverables and their design process to create successful bot experiences.
A malicious use of bots is the coordination and operation of an automated attack on networked computers, such as a denial-of-service attack by a botnet. Internet bots can also be used to commit click fraud and more recently have seen usage around MMORPG games as computer game bots.[citation needed] A spambot is an internet bot that attempts to spam large amounts of content on the Internet, usually adding advertising links. More than 94.2% of websites have experienced a bot attack.[2]
Its a chat-bot — For simplicity reasons in this article, it is assumed that the user will type in text and the bot would respond back with an appropriate message in the form of text (So, we will not be concerned with the aspects like ASR, speech recognition, speech to text, text to speech etc., Below architecture can anyways be enhanced with these components, as required).
Of course, it is not so simple to create an interactive agent that the user will really trust. That’s why IM bots have not replaced all the couriers, doctors and the author of these lines. In this article, instead of talking about the future of chatbots, we will give you a short excursion into the topic of chatbots, how they work, how they can be employed and how difficult it is to create one yourself.
H&M’s consistent increased sales over the past year and its August announcement to launch an eCommerce presence in Canada and South Korea during the fall of 2016, along with 11 new H&M online markets (for a total of 35 markets by the end of the year), appear to signify positive results for its chatbot implementation (though direct correlations are unavailable on its website).
Operator calls itself a “request network” aiming to “unlock the 90% of commerce that’s not on the internet.” The Operator app, developed by Uber co-founder Garrett Camp, connects you with a network of “operators” who act like concierges who can execute any shopping-related request. You can order concert tickets, get gift ideas, or even get interior design recommendations for new furniture. Operator seems to be positioning itself towards “high consideration” purchases, bigger ticket purchases requiring more research and expertise, where its operators can add significant value to a transaction.
In 1950, Alan Turing's famous article "Computing Machinery and Intelligence" was published,[7] which proposed what is now called the Turing test as a criterion of intelligence. This criterion depends on the ability of a computer program to impersonate a human in a real-time written conversation with a human judge, sufficiently well that the judge is unable to distinguish reliably—on the basis of the conversational content alone—between the program and a real human. The notoriety of Turing's proposed test stimulated great interest in Joseph Weizenbaum's program ELIZA, published in 1966, which seemed to be able to fool users into believing that they were conversing with a real human. However Weizenbaum himself did not claim that ELIZA was genuinely intelligent, and the introduction to his paper presented it more as a debunking exercise: