A bot monitors site and records information about the users, such as email, IP, their likes and dislikes. Some bots are employed to get this information and sell it to marketers that ask for certain criteria.

BOT is the short for Robot. Its a software program that imitates the behavior of a human, as by querying search engines or participating in chatroom or IRC discussions. . How it works can be explained only by a software developer.

1) "A chatterbot (or chatbot) is a type of conversational agent, a computer program designed to simulate an intelligent conversation with one or more human users via auditory or textual methods. Such computer programs can also referred to as Artificial Conversational Entities within some specific contexts. Although many chatterbots appear to intelligently interpret human input prior to providing a response, many simply scan for keywords within the input and pull a reply with the most matching keywords or the most similar wording pattern from a local database. Chatterbots may also be referred to as talk bots, chat bots, or chatterboxes. The term "ChatterBot" was originally coined by Michael Mauldin (Creator of the first Verbot, Julia) in 1994 to describe these conversational programs." "Usually a good contextual understanding of a conversation is required to carry out a meaningful dialog, however, many chatterbots do not attempt this level of achievement. Instead they "converse" by recognizing cue words or phrases from the human user, which allows them to use pre-prepared or pre-calculated responses which can move the conversation on in an apparently meaningful way without necessarily requiring the chatterbot to actually understand or comprehend what is being said. Users, especially those unfamiliar with chatterbots, can often find the resulting conversations engaging. Critics of chatterbots call this engagement the ELIZA effect. Some programs classified as chatterbots use other principles. One notable example is Jabberwacky, which attempts to model the way humans learn new language based on user interactions. Others aim to use natural language processing to produce more meaningful responses from an apparent attempted level of understanding of user input." "Automated conversational systems have now progressed from the original designs and applications of the first widely used chatterbots. Currently several large commercial entities such as Lloyds Banking Group, Royal Bank of Scotland, Renault and Citroën are already utilizing virtual assistants to reduce expenditures on call centres and provide a first point of contact that can inform the user exactly of points of interest, provide support, capture data from the user and promote products for sale." "Malicious chatterbots are frequently used to fill chat rooms with spam and advertising, or to entice people into revealing personal information, such as bank account numbers. They are commonly found on Yahoo! Messenger, Windows Live Messenger, AOL Instant Messenger and other instant messaging protocols. There has also been a published report of a chatterbot used in a fake personal ad on a dating service's website." Source and further information: http://en.wikipedia.org/wiki/Chatterbot Further information: http://en.wikipedia.org/wiki/ELIZA 2) "Internet bots, also known as web robots, WWW robots or simply bots, are software applications that run automated tasks over the Internet. Typically, bots perform tasks that are both simple and structurally repetitive, at a much higher rate than would be possible for a human alone. The largest use of bots is in web spidering, in which an automated script fetches, analyses and files information from web servers at many times the speed of a human. Each server can have a file called robots.txt, containing rules for the spidering of that server that the bot is supposed to obey. In addition to their uses outlined above, bots may also be implemented where a response speed faster than that of humans is required (e.g., gaming bots and auction-site robots) or less commonly in situations where the emulation of human activity is required, for example chat bots. These chatterbots may allow people to ask in plain English and then formulate a proper response. These bots can often handle many tasks, including reporting weather, zip-code information, sports scores, converting currency or other units, etc. Others are used for entertainment, such as SmarterChild on AOL Instant Messenger and MSN Messenger and Jabberwacky on Yahoo! Messenger. An additional role of IRC bots may be to lurk in the background of a conversation channel, commenting on certain phrases uttered by the participants (based on pattern matching). This is sometimes used as a help service for new users, or for censorship of profanity. AOL Instant Messenger has now introduced a feature that allows you to make a screen name into a bot. This new feature removes the rate limit on the screen name, but it is now limited in the amount of instant messages that can be sent and received." Source and further information: http://en.wikipedia.org/wiki/Internet_bot 3) Answerbag implemented several questions and answer bots. Those programs were designed to fetch some information in Wikipedia and to generate a question and an answer with it (e.g. Q:"What is the capital of Nevada? A: "Carson City"). From the outside, it could have appeared that real users were asking and answering those questions; however, it was a program. The program could do this automatically because in Wikipedia, that kind of information was presented for all the states in a similar table.

Lots of things can be done by bots from automatically running scheduled maintainance to malicious computer hijacking. Botnets are networks of these working together usually under the control of an indiviual or group. Basically a bot is a piece of software that on one side has a series of functions and on the other has actions in the middle are the triggers. So they can be good or bad but are usually made on the same principles as a computer virus in that they are made as small as possible are effective and will work under certain conditions.