Web technologies

5 Key excerpts on "Web technologies"

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  eBook - PDF

  Web 2.0 and Beyond

  Principles and Technologies

  • Paul Anderson(Author)
  • 2016(Publication Date)
  • Chapman and Hall/CRC

    (Publisher)

  251 C H A P T E R 14 Technology and Standards I n Sections i and ii we considered the powerful ideas and principles that are driving the Web’s development and the online services that are the manifestations of those ideas. Underpinning all this are the Web’s technologies and standards, which we will examine in this chapter. The Web is essentially a client/server system on a global scale (Jazayeri 2007; Akritidis et al. 2011). Users view and interact with websites through Web browsers, which run on their client machines (whether this is a standard PC or Mac, games console or mobile device). These websites are held on Web servers, which sounds rather specialized, but which in fact may only consist of a standard PC hooked up to the Internet and running a piece of soft-ware called, appropriately, a Web server. However, most professional websites such as, say, the webpages of a university or the BBC, are held on specialist, dedicated server machines. These machines ‘serve’ webpage content in response to a request from the client machine’s browser software. This client/server architecture in which one computer, the server, carries out a task on behalf of another—the client—is not unique to the Web and indeed Pressman argues that it now “dominates the landscape of computer-based systems” (Pressman 2000, 764). However, to most people the Web is the clearest everyday manifestation of the client/ server model that they are likely to come across. We begin with a brief review of the way that the Web works, looking at the three funda-mental elements first developed by Tim Berners-Lee and his colleagues at CERN. We will then explore how the technology has evolved, looking in particular at a technique known as Ajax and reviewing the many server-side developments that have assisted in providing the sophisticated and responsive user interfaces that are a feature of the modern Web.

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  eBook - PDF

  Web Engineering

  The Discipline of Systematic Development of Web Applications

  • Gerti Kappel, Birgit Pröll, Siegfried Reich, Werner Retschitzegger, Gerti Kappel, Birgit Prouml;ll, Siegfried Reich, Werner Retschitzegger, Gerti Kappel, Birgit Prouml;ll, Siegfried Reich, Werner Retschitzegger(Authors)
  • 2014(Publication Date)
  • Wiley

    (Publisher)

  The Semantic Web (described in Chapter 14) is an ongoing effort to address this issue. Together with other emerging technologies such as context awareness support, new foundations are being laid out to enable the Web to become a more proactive source of knowledge. 111 6 Technologies for Web Applications Martin Nussbaumer, Martin Gaedke The choice of appropriate technologies is an important success factor in the development of Web applications. We need to know the characteristics of technologies to be able to use them meaningfully. In addition to knowing the relevant technologies, the implementation of Web applications often requires knowledge of how different technologies interact in an existing architecture. This chapter gives an overview of various technologies and their interplay and usage in a few selected architecture examples, based mainly on the World Wide Web Consortium’s (W3C) recommendations. 6.1 Introduction Conventional software-system development is the process of designing a correct HOW for a well-defined WHAT. Patridge (1992) Once we have defined the requirements of a Web application, chosen an architecture, and developed a design, etc., in short, once we have clarified the “what”, we are ready to start the implementation phase, i.e., the “how”. In this context, reusability plays an increasingly important role in the development process. The resulting requirements to the implementation of Web applications begin with the choice of appropriate technologies. The requirements for the key principle described in Chapter 5, i.e., separation of content and presentation, is a central requirement to appropriately use technologies. In addition, we have to consider requirements for the distribution and integration of other systems according to a selected or existing architecture. The specifics of implementation technologies for Web applications versus “conventional” soft- ware systems stem from the use of Web standards.

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  eBook - PDF

  New Perspectives Computer Concepts 2016 Enhanced, Introductory

  • June Jamrich Parsons; Dan Oja, June Jamrich Parsons, Dan Oja(Authors)
  • 2016(Publication Date)
  • Cengage Learning EMEA

    (Publisher)

  Figure 4-1 lists the essen-tial Web technologies that you’ll learn about in this unit. FIGURE 4-1: ESSENTIAL Web technologies Terminology The process of accessing a Web site is sometimes referred to as surfing the Web and visitors are called Web surfers . QUICKCHECK Content is the main emphasis for which of the following? a. The Internet b. The Web c. CSS d. URLs HTTP A standard protocol for communication between browsers and Web servers HTML The markup language used to specify the contents of a Web page CSS The tool used to for-mat text and layout for Web pages URLs The unique identifi-ers for Web pages BROWSERS The software used to get and display Web pages HYPERTEXT LINKS The set of connec-tions between Web pages Copyright 2017 Cengage Learning. All Rights Reserved. May not be copied, scanned, or duplicated, in whole or in part. Due to electronic rights, some third party content may be suppressed from the eBook and/or eChapter(s). Editorial review has deemed that any suppressed content does not materially affect the overall learning experience. Cengage Learning reserves the right to remove additional content at any time if subsequent rights restrictions require it. 2 3 6 SECTION A, UNIT 4 EVOLUTION According to MIT researcher Matthew Gray, in June 1993 there were a total of 130 Web sites containing linked documents. By January 1996, there were 100,000 Web sites. Today, there are more than a billion Web sites and new sites appear every day. The remarkable story of such explosive growth began more than half a century ago.  How did the Web evolve? In 1945, an engineer named Vannevar Bush described a microfilm-based machine called the Memex that linked associated information or ideas through “trails.” By following trails from one document to another, readers could track down ideas from within an exten-sive library of information. Bush’s Memex was hypothetical, however; the microfilm readers and analog computers of the time were not suitable for such a complex task.

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  Designing Data-Intensive Web Applications

  • Stefano Ceri, Piero Fraternali, Aldo Bongio, Marco Brambilla, Sara Comai, Maristella Matera(Authors)
  • 2003(Publication Date)
  • Morgan Kaufmann

    (Publisher)

  TECHNOLOGY OVERVIEW Chapter 1 Technologies for Web Applications I P A R T . This Page Intentionally Left Blank 1.1 Introduction 1.2 HTTP and HTML: The Foundation of Web Technology 1.3 XML: eXtensible Markup Language 1.4 SQL: The Structured Query Language for Relational Databases 1.5 Beyond HTTP: Building Web Pages on the Fly Summary Bibliographic Notes 1.1 Introduction Web applications are complex systems, based on a variety of hardware and soft-ware components, protocols, languages, interfaces, and standards. This chapter proposes a “guided tour” through the ingredients that characterize Web applica-tions; the progression of arguments is such that every new development can be interpreted as the natural consequence of problems exhibited by previous tech-nological solutions. This approach may help you in consolidating within a clear reference framework some background knowledge you might have already, but perhaps not systematically organized. The review starts with the basic technologies for building Web applications: HTTP—the resource transfer protocol—and HTML—the language for writing Te c h n o l o g i e s f o r We b A p p l i c a t i o n s 1 C H A P T E R hypertexts. The first section also describes client-side scripts and components that make a Web interface more interactive. HTTP and HTML alone enable the devel-opment of simple Web sites, but are insufficient for large and complex applica-tions; in particular, HTML is limited in the number and expressive power of its tags, which embed presentation features inside pages. However, the latest version of HTML (HTML 4), and specifically the introduction of cascading style sheets, moves in the direction of separating content from presentation, which is essen-tial for large scale applications.

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  eBook - ePub

  Developing Effective Websites

  A Project Manager's Guide

  • Roy Strauss, Patrick Hogan(Authors)
  • 2013(Publication Date)
  • Routledge

    (Publisher)

  www.w3c.org > are HTML and CSS (cascading style sheets) validation. The W3C website is a good place to check out established and evolving standards. The standards process is necessarily slow, subject to debate, discussion, and deliberations in order to negotiate a common middle ground among sometimes competing technologies. The standards cannot possibly keep up with the rate of innovation coming from individual companies. Website project managers should be able to distinguish between emerging technologies, which raise questions of portability and interoperability, and established standards, which are always safer but not cutting edge.

  SERVERS AND Web technologies

  Move over, you flashy designers and hotshot producers. The real action of the Web is on the server. Unfortunately, to much confusion, the term Web server is used interchangeably to refer to hardware, software, or both. At the most basic level, the server receives requests from the clients around the Internet and serves up the requested files. In sum, it performs a myriad of other functions that keep a website humming. The specialized services that are capturing the public’s interest in the Internet, such as e-commerce, distance learning, online auctions, or file-sharing services, all depend on sophisticated server software and programming.

  SERVER HARDWARE AND SOFTWARE

  The tasks that the machine performs define a server, not the hardware itself. Theoretically, just about any computer running any operating system can be used as a server, whether an old 486 desktop, a laptop, or a mainframe; however, Web servers are usually rack-mounted boxes with a powerful processor and lots of storage and memory.

  The location and spatial requirements of servers also vary. A small operation may serve its needs with a desktop computer. You will also see small racks or huge racks with hundreds of servers rarely touched by human hands. Fundamentally, the server is a computer that is attached to the Internet and can run the required software.

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