History Of Computer: Basic Computing Periods PDF

# History of Computer: Basic Computing Periods ## Definition of Computer: * A programmable machine. * An electronic device that manipulates information, or data. It has the ability to store, retrieve, and process data. * A machine that manipulates data according to a list of instructions (program...

# History of Computer: Basic Computing Periods ## Definition of Computer: * A programmable machine. * An electronic device that manipulates information, or data. It has the ability to store, retrieve, and process data. * A machine that manipulates data according to a list of instructions (program). * A device that aids humans in performing various kinds of computations or calculations. ## Three Principal Characteristics of a Computer: * It responds to a specific set of instructions in a well-defined manner. * It can execute a pre-recorded list of instructions. * It can quickly store and retrieve large amounts of data. ## History of Computer: Basic Computing Periods * **Earliest Computers** calculations were computed by humans, whose job title was computers. * These human computers were typically engaged in the calculation of a mathematical expression. * The calculations of this period were specialized and expensive, requiring years of training in mathematics. * The first use of the word "computer" was recorded in 1613, referring to a person who carried out calculations, or computations, and the word continued to be used in that sense until the middle of the 20th century. ## History of Computer: Basic Computing Periods ### Tally Sticks * A tally stick was an ancient memory aid device to record and document numbers, quantities, or even messages. ### Abacus * A mechanical device used to aid an individual in performing mathematical calculations. * The abacus was invented in Babylonia in 2400 B.C. * The abacus in the form we are most familiar with was first used in China in around 500 B.C., and is used to perform basic arithmetic operations. ## History of Computer: Basic Computing Periods ### Napier's Bones * Invented by John Napier in 1614, and allowed the operator to multiply, divide and calculate square and cube roots by moving the rods around and placing them in specially constructed boards. ### Slide Rule * Invented by William Oughtred in 1622 * Based in Napier's ideas about logarithms. * Used primarily for multiplication, division, roots, logarithms, and trigonometry. * Not normally used for addition or subtraction. ## History of Computer: Basic Computing Periods ### Pascaline * Invented by Blaise Pascal in 1642. * It was limited to addition and subtraction. * It was too expensive. ### Stepped Reckoner * Invented by Gottfried Wilhelm Leibniz in 1672. * The machine that can add, subtract, multiply, and divide automatically. ## History of Computer: Basic Computing Periods ### Jacquard Loom * A mechanical loom, invented by Joseph-Marie Jacquard in 1881. * An automatic loom controlled by punched cards. ### Arithmometer * A mechanical calculator invented by Thomas de Colmar in 1820. * The first reliable, useful, and commercially successful calculating machine. * The machine could perform the four basic mathematic functions. * The first mass-produced calculating machine. ## History of Computer: Basic Computing Periods ### Difference Engine and Analytical Engine * An automatic, mechanical calculator designed to tabulate polynomial functions. * Invented by Charles Babbage in 1822 and 1834 * It is the first mechanical computer. ### First Computer Programmer * In 1840, Augusta Ada Byron suggests to Babbage that he use the binary system. * She writes programs for the Analytical Engine. ## History of Computer: Basic Computing Periods ### Scheutzian Calculation Engine * Invented by Per Georg Scheutz in 1843. * Based on Charles Babbage's difference engine. * The first printing calculator. ### Tabulating Machine * Invented by Herman Hollerith in 1890. * To assist in summarizing information and accounting. ## History of Computer: Basic Computing Periods ### Harvard Mark 1 * Also known as IBM Automatic Sequence Controlled Calculator (ASCC). * Invented by Howard H. Aiken in 1943 * The first electro-mechanical computer. ### Z1 * The first programmable computer. * Created by Konrad Zuse in Germany from 1936 to 1938. * To program the Z1 required that the user insert punch tape into a punch tape reader and all output was also generated through punch tape. ## History of Computer: Basic Computing Periods ### Atanasoff-Berry Computer (ABC) * It was the first electronic digital computing device. * Invented by Professor John Atanasoff and graduate student Clifford Berry at Iowa State University between 1939 and 1942. ### ENIAC * ENIAC stands for Electronic Numerical Integrator and Computer. * It was the first electronic general-purpose computer. * Completed in 1946. * Developed by John Presper Eckert and John Mauchly. ## History of Computer: Basic Computing Periods ### UNIVAC 1 * The UNIVAC I (UNIVersal Automatic Computer 1) was the first commercial computer. * Designed by John Presper Eckert and John Mauchly. ### EDVAC *EDVAC stands for Electronic Discrete Variable Automatic Computer * The First Stored Program Computer * Designed by Von Neumann in 1952. * It has a memory to hold both a stored program as well as data. ## History of Computer: Basic Computing Periods ### The First Portable Computer * Osborne 1 - the first portable computer. * Released in 1981 by the Osborne Computer Corporation. ### The First Computer Company * The first computer company was the Electronic Controls Company. * Founded in 1949 by John Presper Eckert and John Mauchly. # Four Stages of Information Technology Development * **a) Premechanical** - the premechanical age is the earliest age of information technology. It can be defined as the time between 3000B.C. and 1450A.D. * **b) Mechanical** - the mechanical age is when we first start to see connections between our current technology and its ancestors. The mechanical age can be defined as the time between 1450 and 1840. * **c) Electromechanical** - some technologies that resemble our modern-day technology. The electromechanical age can be defined as the time between 1840 and 1940. These are the beginnings of telecommunication. * **d) Electronic** - the electronic age is what we currently live in. It can be defined as the time between 1940 and right now. The ENIAC was the first high-speed, digital computer capable of being reprogrammed to solve a full range of computing problems. # Pre-Mechanical Age: 3000 B.C. – 1450 A.D. * **1. Writing and Alphabets - communication**. * **Petroglyph** - first humans communicated only through speaking and picture drawings. * 3000 B.C., the Sumerians in Mesopotamia (what is today southern Iraq) devised Cuniform. * The Greeks later adopted the Phoenician alphabet and added vowels; the Romans gave the letters Latin names to create the alphabet we use today. * **3. Books and Libraries: Permanent Storage Devices**. * Religious leaders in Mesopotamia kept the earliest "books" * The Egyptians kept scrolls. * Around 600 B.C., the Greeks began to fold sheets of papyrus vertically into leaves and bind them together. * **4. The First Numbering Systems**. * **Egyptian System:** * The numbers 1-9 as vertical lines, the number 10 as a n or circle, the number 100 as a coiled rope, and the number 1,000 as a lotus blossom. * The first numbering systems like those in use today were invented between 100 and 200 A.D. by Hindus in India who created a nine-digit numbering system. * Around 875 A.D., the concept of zero was developed. * **5. The First Calculators: The Abacus.** * One of the very first information processors. # Mechanical Age: 1450 – 1840 * **1. The First Information Explosion.** * Johann Gutenberg invented the movable metal-type printing process in 1450. * The development of book indexes and the widespread use of page numbers. * **2. Calculating Machine** * Wilhelm Schickard invented the first mechanical calculator in 1623 that can work with six digits and can carries digits across columns. * **3. Pascaline** * The Pascaline. Invented by Blaise Pascal (1642) (made of clock gears and levers) that could solve mathematical problems like addition and subtraction. * **4. Babbage's Engines** * Charles Babbage - invented the difference engine (1821) and analytical engine (1832). Father of modern computer. # Electromechanical Age: 1840 – 1940 * **1. Morse Code: 1835** * Samuel Morse conceived of his version of an Electromagnetic Telegraph (Dots and Dashes) * **2. Telephone and Radio: 1876** * Alexander Graham Bell developed the first working telephone. * **3. Comptograph: 1885** * Dorr Felt invented first adding and subtracting calculator. * Comptograph containing a built-in printer. * **4. Punch Card: 1890** * Piece of stiff paper that contains digital information represented by the presence or absence of holes in predefined positions. # Electronic Age: 1941 – Present * **1. Z1: 1941** * Konrad Zuse - Built the first programmable computer called Z3. * **2. Mark I: 1942** * John von Neumann - Build the first stored program computer. * 8 feet tall, 51 feet long, 2 feet thick, weighed 5 tons, used about 750,000 parts, 500 miles of wires. * **3. ABC Computer: 1942** * John Atanasoff and Clifford Berry. * Completed the first all-electronic computer called ABC or Atanasoff-Berry Computer. * Foundation for advances in electronic digital computers. # Milestone in Computer History ## History of Computer: Generations of Computer * There are five generations of computer: * First generation - 1946 to 1958 * Second generation - 1959 to 1964 * Third generation - 1965 to 1970 * Fourth generation - 1971 to Today * Fifth generation - Today to future ### The First Generation * The first computers used vacuum tubes for circuitry and magnetic drums for memory, and were often enormous, taking up entire rooms. They were very expensive to operate and in addition to using a great deal of electricity, generated a lot of heat, which was often the cause of malfunctions ## The Second Generation * Transistors replaced vacuum tubes and ushered in the second generation of computers. One transistor replaced the equivalent of 40 vacuum tubes. Allowing computers to become smaller, faster, cheaper, more energy-efficient and more reliable. Still generated a great deal of heat that can damage the computer. ### The Third Generation * The development of the integrated circuit was the hallmark of the third generation of computers. Transistors were miniaturized and placed on silicon chips, called semiconductors, which drastically increased the speed and efficiency of computers. It could carry out instructions in billionths of a second. Much smaller and cheaper compare to the second-generation computers. ### The Fourth Generation * The microprocessor brought the fourth generation of computers, as thousands of integrated circuits were built onto a single silicon chip. As these small computers became more powerful, they could be linked together to form networks, which eventually led to the development of the Internet. ### The Fifth Generation * Based on Artificial Intelligence (AI). Still in development. The use of parallel processing and superconductors is helping to make artificial intelligence a reality. The goal is to develop devices that respond to natural language input and are capable of learning and self-organization. There are some applications, such as voice recognition, that are being used today. # Applications of ICT (Computers) in Our Daily Lives ## Business * Store and maintain accounts, personnel records, manage projects, track inventory, create presentations and reports. * Enable communication with people both within and outside the business, using various technologies, including e-mail. * Can be used to promote the business and enable direct interaction with customers. ## Education * Can be used to give learners audio-visual packages, interactive exercises, and remote learning, including tutoring over the internet. * Can be used to access educational information from intranet and internet sources, or via e-books. * Can be used to maintain and monitor student performance, including through the use of online examinations, as well as to create projects and assignments. ## Healthcare * Easier to store and access patient data, complex information can also be analyzed by software to aid discovery of diagnoses, as well as search for risks of diseases. * Computers control lab equipment, heart rate monitors, and blood pressure monitors. * Enable doctors to have greater access to information on the latest drugs, as well as the ability /to share information on diseases with other medical specialists. ## Retail and Trade * Can be used to buy and sell products online. * Enables sellers to reach a wider market with low overheads, and buyers to compare prices, read reviews, and choose delivery preferences. * Can be used for direct trading and advertising, using sites, social media or independent websites. ## Government * Improve the quality and efficiency of their services. * Examples include city planning, law enforcement, traffic, and tourism. * Can be used to store information, promote services, communicate internally and externally, as well as for routine administrative purposes. ## Marketing * Enable marketing campaigns to be more precise through the analysis and manipulation of data. T * Facilitate the creation of websites and promotional materials. * Can be used to generate social media campaigns. * Enable direct communication with customers through email and online chat. ## Science * Scientists were one of the first groups to adopt computers as a work tool. * Can be used for research, sharing information with other specialists both locally and internationally, as well as collecting, categorizing, analyzing, and storing data. * Computers also play a vital role in launching, controlling, and maintaining space craft, as well as operating other advanced technology. ## Publishing * Can be used to design pretty much any type of publication. * Include newsletters, marketing materials, fashion magazines, novels, or newspapers. * Computers are used in the publishing of both hard-copy and e-books. * They are also used to market publications and track sales. ## Arts and Entertainment * Can be used to create drawings, graphic designs, and paintings. * Can be used to edit, copy, send, and print photographs. They can be used by writers to create and edit. * Can be used to make, record, edit, play, and listen to music. * Can be used to capture, edit and watch videos. * Can be used for playing games. ## Communication * Real-time communication over the internet easy, thanks to software and videoconferencing services such as Skype. * Families can connect with audio and video, businesses can hold meetings between remote participants, * News organizations can interview people without the need for a film crew. ## Banking and Finance * Most banking in advanced countries now takes place online. * Can use computers to check your account balance, transfer money, or pay off credit cards. * Can also use computer technology to access information on stock markets, trade stocks, and manage investments. * Banks store customer account data, as well as detailed information on customer behavior which is used to streamline marketing. ## Transport * Road vehicles, trains, planes, and boats are increasingly automated with computers being used to maintain safety and navigation systems, and increasingly to drive, fly, or steer. * Can also highlight problems that require attention, such as low fuel levels, oil changes, or a failing mechanical part. * Can be used to customize settings for individuals. * Example, seat setup, air-conditioning temperatures. ## Navigation * Computer technology has been combined with GPS technology. * Computers combined with satellites mean that it's now easy to pinpoint your exact location, know which way that you are moving on a map, * Good idea of amenities and places of interest around you. ## Working From Home * Working from home and other forms of remote working increasingly common. * Workers can access necessary data, communicate, and share information without commuting to a traditional office. * Managers are able to monitor workers' productivity remotely. ## Military * Use for training purposes. * Used for analyzing intelligence data. * Used to control smart technology, such as guided missiles and drones, as well as for tracking incoming missiles and destroying them. * Work with other technologies such as satellites to provide geospatial information and analysis. * Help tanks and planes to target enemy forces. ## Social and Romance * Social media enables people to chat in text or audio in real time across large distances, * Exchange photographs, videos, and memes. * Dating sites and apps help people to find romance. * Online groups help people to connect with others who have similar interests. ## Booking Vacations * Can be used by travelers to study timetables, examine route options, and buy plane, train, or bus tickets. * Can be used to explore and book accommodation, whether traditional hotels, or through newer services. * Guided tours, excursions, events, and trips can also be explored and booked online using computers. ## Security and Surveillance * Increasingly being combined with other technologies to monitor people and goods. * Computers combined with biometric passports make it harder for people to fraudulently enter a country or gain access to a passenger airplane. * Face-recognition technology makes it easier to identify terrorists or criminals in public places. * Driver plates can be auto scanned by speed cameras or police cars. * Private security systems have also become much more sophisticated with the introduction of computer technology and internet technology. ## Weather Forecasting * World's weather is complex and depends upon a multitude of factors that are constantly changing. * It's impossible for human beings to monitor and process all the information coming in from satellite and other technologies, never mind perform the complex calculations that are needed to predict what is likely to happen in the future. * Computers can process the large amounts of meteorological information. ## Robotics * Robotics is an expanding area of technology which combines computers with science and engineering to produce machines that can either replace humans, or do specific jobs that humans are unable to do. * One of the first use of robotics was in manufacturing to build cars. Since then, robots have been developed to explore areas where conditions are too harsh for humans, to help law enforcement, to help the military, and to assist healthcare professionals. # The Web * The Web (World Wide Web) consists of information organized into Web pages containing text and graphic images. The world wide web is larger collection of interconnected documents or content. It contains hypertext links, or highlighted keywords and images that lead to related information. A collection of linked Web pages that has a common theme or focus is called a Web site. The main page that all of the pages on a particular Web site are organized around and link back to is called the site's home page. Sir Timothy John Berners-Lee, OM, KBE, FRS, FREng, FRSA, DFBCS, RDI, also known as TimBL, is an English engineer and computer scientist best known as the inventor of the World Wide Web. He is a Professorial Fellow of Computer Science at the University of Oxford and a professor at the Massachusetts Institute of Technology. ## A. Web 1.0 (Read Only Static Web) * It is an old internet that only allows people to read from the internet. First stage worldwide linking web pages and hyperlink. Web is use as "information portal". It uses table to positions and align elements on page. * Most read only web. * If focused on company's home pages. * Dividing the world wide web into usable directories * It means web is use as "Information Portal" * It started with the simple idea "put content together" * Example of Web 1.0 * Mp3.com * Home Page * Directories * Page Views * HTML/Portals. * Disadvantages * Read only web * Limited user interaction * Lack of standards ## B. Web 2.0 (Read-write interactive web) * A term used to describe a new generation of Web services and applications with an increasing emphasis on human collaboration. * It is a platform that gives users the possibility (liberty) to control their data. * This is about user-generated content and the read-write web. * People are consuming as well as contributing information through blogs or sites. * Allows the user to interact with the page known as DYNAMIC PAGE; instead of just reading a page, the user may be able to comment or create a user account. Dynamic page refers to the web pages that are affected by user input or preference. * Is focused on the ability for people to collaborate and share information online via social media, blogging and Web-based communities. * Example of Web 2.0 are the following: * **Social Networking** is the use of Internet-based social media sites to stay connected with friends, family, colleagues, customers, or clients. Social networking can have a social purpose, a business purpose, or both, through sites such as: * Example * Facebook * Twitter * LinkedIn * Google+ * Pinterest * Tumblr * Instagram * **Blogs** is a discussion or informational website published on the world wide web consisting of discrete, often informal diary-style text entries (posts). Posts are typically displayed in reverse chronological order, so that the most recent post appears first, at the top of the web page. * Example * WordPress * Blogger * Tumbler * **Wikis** is a hypertext publication collaboratively edited and managed by its own audience directly using a web browser. A typical wiki contains multiple pages for the subjects or scope of the project and may be either open to the public or limited to use within an organization for maintaining its internal knowledge base. * Example * Wikipedia * Workbooks * Wikiversity * Commons * Wiktionary * Wikiquote * Wikivoyage * Wikidata * Wikinews * Wikispecies * **Video Sharing Sites** a website that lets people upload and share their video clips with the public at large or to invited guests. * Example: * YouTube * Facebook * LinkedIn * Flickr * Photobucket * LinkedIn * Flickr ## C. Web 3.0: (Read-write intelligent web) * Suggested name by John Markoff of the New York Times for the third generation of the web. * In this generation, all the application on web or mobile will be upgraded with more features. * It applies same principles as Web 2.0: two-way interaction. * Web 3.0 will be more connected, open, and intelligent, with semantic web technologies, distributed databases, natural language processing, machine learning, machine reasoning and autonomous agents. * Semantic Web provides a framework that allows data to be shared and reuse to deliver web content specifically targeting the user. * It is a web of data. * Changing the web into a language that can be read and categorized by the system rather than humans. # Types of Websites ## eCommerce * Website is a website people can directly buy products from you've probably used a number of eCommerce websites before, most big brands and plenty of smaller ones have one. Any website that includes a shopping cart and a way for you to provide credit card information to make a purchase falls into this category. ## Business Website * Any website that's devoted to representing a specific business. It should be branded like the business (the same logo and positioning) and communicate the types of products and/or services the business offers. ## Entertainment Website * If you think about your internet browsing habits, you can probably think of a few websites that you visit purely for entertainment purposes. ## Portfolio Website * Sites devoted to showing examples of past work. Service providers who want to show potential clients the quality of the work they provide can use a portfolio website to collect some of the best samples of past work they've done. This type of website is simpler to build than a business website and more focused on a particular task: collecting work samples. ## Brochure Website * A simplified form of business websites. For businesses that know they need an online presence, but don't want to invest a lot into it (maybe you're confident you'll continue to get most of your business from other sources), a simple brochure site that includes just a few pages that lay out the basics of what you do and provide contact information may be enough for you. ## Nonprofit Website * In the same way that businesses need websites to be their online presence, nonprofits do as well. A nonprofit website is the easiest way for many potential donors to make donations and will be the first place many people look to learn more about a nonprofit and determine if they want to support it. ## Educational Website * The websites of educational institutions and those offering online courses fall into the category of educational websites. These websites have the primary goal of either providing educational materials to visitors or providing information on an educational institution to them. ## Infopreneur Website * Websites overlap a bit with business and eCommerce websites, but they represent a unique type of online business. Infopreneurs create and sell information products. That could be in the form of courses, tutorials, videos or eBooks. ## Personal Website * Not all websites exist to make money in some way or another. Many people find value in creating personal websites to put their own thoughts out into the world. This category includes personal blogs, vlogs, and photo diaries people share with the world. ## Web Portal * A websites designed for internal purposes at a business, organization, or institution. They collect information in different formats from different sources into one place to make relevant information accessible to the people who need to see it. They often involve a login and personalized views for different users that ensure the information that's accessible is most useful to their particular needs. ## Wiki or Community Forum Website * Most people are familiar with wikis through the most famous example of one out there: Wikipedia. But wikis can be created on pretty much any subject you can imagine. A wiki is any website where various users are able to collaborate on content and all make their own tweaks and changes as they see fit. There are wikis for fan communities, for business resources, and for collecting valuable information sources. # The Internet * Internet or "net" (network of network) is the largest computer network in the world that connects billions of computer user. The word internet comes from combination between "interconnection" and "network". Network is a collection of computers and devices connected via communication channels and transmission media allow to share resources (hardware, software, data, information). Generally, nobody owns the internet. ## A. Brief History of Internet * **ARPA** - Advanced Research Project Agency January 2, 1969 started an experimental computer network. * **Concept** - No server, but equal importance/participation to every computer in the network. Even if, one or two node destroyed that will now affect the network. In 1982 the word internet started. 1986 First" free net" created in Case Western Reserve University 1991: US government allowed business agencies to connect to internet. Now all people can connect to the internet and improve their life and work quality. The internet support various aspects in our life. Vinton Gray Cerf ForMemRS is an American Internet pioneer and is recognized as one of "the fathers of the Internet", sharing this title with TCP/IP co-developer Bob Kahn. ## B. Major Components of the Internet * **1. Servers** - is a computer program that provides service to another computer program and it's user. * **Types of Servers** * Application Server a program in computer that provides the business logic for an application program. * Web Server a computer program that serves requested HTML pages or files. * Proxy Server is a software that acts as an intermediary between an endpoint device, such as computer and another server from which a user is requesting. * **Mail Server** - is an application that receives incoming e-mail from local users and remote senders and forward outgoing e-mail for delivery. * **File Server** is a computer responsible for central storage and management of data files so that another computer on the same network can access them. * **Policy Server** is a security component of a policy-based network that provides authorization services and facilities tracking and control of files. ## 2. IP Address (Internet Protocol) * This is a numerical label assigned to each device. This provides identity to a network device. ## 3. Browser * An application program that provides a way to look information on the web. * Example of browsers: Google chrome, safari, internet explorer, opera, Mozilla ## 4. Domain Name System (DNS) * The phonebook of internet. We access information online through domain names. * Example of DNS. | Name | Entity | |---|---| | .com | Commercial | | .org | Organization | | .net | Network | | .edu | Education | | .gov | Government and State Government Agencies | | .ph | Philippines | | .au | Australia | ## 5. Internet Service Provide (ISP) * Is an organization that provides services for accessing, using or participating in the internet. * **Two types of ISP:** * **National ISP** - provided internet access to a specific geographic area. * **Regional ISP** - business that provides internet access in cities and towns nationwide. * **Example of ISP:** Sky Broadband, PLDT, Converge ## C. Uses of Internet * **Look for information** * School works, jobs, and home purposes * Send and receive electronic mail * Video teleconferencing (video call, video chat) * Buy and sell product * **Social networking** * Watch & post videos * Games * Take college courses * Monitor home while away * Financial transactions ## D. Internet Terms and Definition * **Internet** A global network of thousands of computer networks linked by data lines and wireless systems. * **Web** a collection of billions of webpages that you can view with a web browser. * **Email** the most common method of sending and receiving messages online. * **Social media** websites and apps that allow people to share comments, photos, and videos. * **Online gaming** games that allow people to play with and against each other over the Internet. * **Software updates** - operating system and application updates can typically downloaded from the Internet * **HTML** - Hypertext Markup Language is a coding language used to tell a browser how to place pictures, text, multimedia, and links to create a web page. When a user clicks on a link within a web page, that link, which is coded with HTML, links the user to a specific linked web page. * **URL** Uniform Resource Locator is a web address used to connect to a remote resource on the world wide web. * **Bit** is a single digit in the binary numbering system (base 2). For example: 1 is a bit or 0 is a bit. * **Byte** - generally consists of eight bits. * **Upload** To upload is to transfer data from your computer to another computer. * **Download** To download is to transfer data from ## **HTTP** * The acronym for Hypertext Transfer Protocol, the data communication standard of web pages. When a web page has this prefix, the links, text, and pictures should work correctly in a web browser. ## **HTTPS** * The acronym for Hypertext Transfer Protocol Secure. This indicates that the web page has a special layer of encryption added to hide your personal information and passwords from others. ## **Router** * Or router-modem combination is the hardware device that acts as the traffic cop for network signals arriving at your home or business from your ISP. A router can be wired or wireless or both. ## **Encryption** * Is the mathematical scrambling of data so that it is hidden from eavesdroppers. Encryption uses complex math formulas to turn private data into meaningless gobbledygook that only trusted readers can unscramble. ## **Web Bot** * A term that applies to programs/applets (macros and intelligent agents) used on the Internet. Such bots perform a repetitive function, such as posting messages to multiple newsgroups or doing searches for information. ## **Search Engine** * Specialized software, such as Google and Yahoo, that lets www browser users search for information on the web by using keywords, phrases.