Copyright Goodheart-Willcox Co., Inc. 6 Introduction to Microsoft Offi ce hubs and switches, as shown in Figure 1-3. This marks the beginning of the third phase of the digital revolution, which would last through the early 2000s. Internet The Internet began as a project in the 1960s called ARPANET. The network was known as the wide area network (WAN). It was connected to the National Science Foundation network (NSFNET) in 1990, and in 1995 the last restrictions on its commercial use were eliminated. The Internet will be discussed in further detail later in this chapter. World Wide Web The World Wide Web (WWW), or the web, is a part of the Internet. The web uses the Internet, but the Internet and the web are not the same thing. The World Wide Web was launched in 1991. The World Wide Web was conceived and developed by Sir Tim Berners-Lee. The World Wide Web will be discussed in further detail later in this chapter. Mobile Computers Mobile devices are commonplace today. These are small, typically handheld digital devices that rely on satellite, microwave, and cellular transmissions for data transfer. Examples of mobile devices are cellular telephones and smartphones, tablet computers, e-book readers, and global positioning system (GPS) devices. Cloud Computing The fourth and current phase of the digital revolution began in the early 2000s when cloud computing appeared. Cloud computing involves storing and retrieving data from Internet-based spaces. Collectively, these spaces are called the cloud. The cloud is useful for backing up and sharing data, but it also made possible running a program that was not installed on the local computer. The cloud involves shared resources among computers. Communication Technologies Computer technology has made it possible for those with access to digital communication devices to stay in touch with others 24 hours a day. As a result, communication methods are changing at a rapid pace. Speed In the past, a person had to wait days for the post offi ce to carry written communication in the form of a letter. The Internet has reduced waiting time for written communication to nanoseconds. Even spoken communication is carried over the Internet in real-time. Bandwidth is FYI The concept of cloud computing dates to the 1950s. Functional precursors to the cloud began appearing in the 1990s. Arjuna Kodisinghe/Shutterstock.com Figure 1-3. Computer networks can be very large and may contain many servers to manage data.