The term Chatbot is closely related to chat bot and chatterbot. Chatterbot is more popular in relation to chatbot who talk a lot, and is not necessary very intelligent in processing the user answers. Chat bot is used by technical people who consider the word ‘bot’ as a normal term for ‘robotised actions’, and for them ‘chat bot’ is a special kind of bot. The term Chatbot is actually the most popular amongst these three terms and has the broadest meaning.

Chatbot, when it plays its role as a virtual representative of an enterprise, is widely used by businesses outside of the US, primarily in the UK, The Netherlands, Germany and Australia. Additionally, the usage of this term is quite popular amongst amateur AI enthusiasts willing to spend vast amounts of time on their own intelligent creations (with diverse outcomes).

The word bot, in Internet sense, is a short form of robot and originates from XX century. The modern use of the word bot has curious affinities with earlier uses, e.g. “parasitical worm or maggot” (1520s), of unknown origin; and Australian-New Zealand slang “worthless, troublesome person” (World War I -era). The method of minting new slang by clipping the heads off respectable words does not seem to be old or widespread in English. Examples: za from pizza, zels from pretzels, rents from parents, are American English student or teen slang and seem to date back no further than late 1960s.[4]
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.
“It’s hard to balance that urge to just dogpile the latest thing when you’re feeling like there’s a land grab or gold rush about to happen all around you and that you might get left behind. But in the end quality wins out. Everyone will be better off if there’s laser focus on building great bot products that are meaningfully differentiated.” — Ryan Block, Cofounder of