Data center. An operation engineer overseeing a network operations control room of a data center A data center is a facility used to house computer systems and associated components, such as telecommunications and storage systems. It generally includes redundant or backup power supplies, redundant data communications connections, environmental controls (e.g., air conditioning, fire suppression) and various security devices. Large data centers are industrial scale operations using as much electricity as a small town[1] and sometimes are a significant source of air pollution in the form of diesel exhaust.[2] History[edit] Data centers have their roots in the huge computer rooms of the early ages of the computing industry. The boom of data centers came during the dot-com bubble. With an increase in the uptake of cloud computing, business and government organizations are scrutinizing data centers to a higher degree in areas such as security, availability, environmental impact and adherence to standards.
How to Merge Web Pages Into One. The Internet Infrastructure. Common Web Protocols. Hypertext Transfer Protocol. The Hypertext Transfer Protocol (HTTP) is an application protocol for distributed, collaborative, hypermedia information systems.[1] HTTP is the foundation of data communication for the World Wide Web. The standards development of HTTP was coordinated by the Internet Engineering Task Force (IETF) and the World Wide Web Consortium (W3C), culminating in the publication of a series of Requests for Comments (RFCs), most notably RFC 2616 (June 1999), which defined HTTP/1.1, the version of HTTP most commonly used today.
In June 2014, RFC 2616 was retired and HTTP/1.1 was redefined by RFCs 7230, 7231, 7232, 7233, 7234, and 7235.[2] HTTP/2 is currently in draft form. Technical overview[edit] URL beginning with the HTTP scheme and the WWW domain name label. A web browser is an example of a user agent (UA). HTTP is designed to permit intermediate network elements to improve or enable communications between clients and servers. History[edit] The first documented version of HTTP was HTTP V0.9 (1991). Internet Protocol. This article is about the IP network protocol only. For Internet architecture or other protocols, see Internet protocol suite.
The Internet Protocol (IP) is the principal communications protocol in the Internet protocol suite for relaying datagrams across network boundaries. Its routing function enables internetworking, and essentially establishes the Internet. Historically, IP was the connectionless datagram service in the original Transmission Control Program introduced by Vint Cerf and Bob Kahn in 1974; the other being the connection-oriented Transmission Control Protocol (TCP). The Internet protocol suite is therefore often referred to as TCP/IP. The first major version of IP, Internet Protocol Version 4 (IPv4), is the dominant protocol of the Internet. Function[edit] The Internet Protocol is responsible for addressing hosts and for routing datagrams (packets) from a source host to a destination host across one or more IP networks. Datagram construction[edit] Reliability[edit] File Transfer Protocol.
FTP is built on a client-server architecture and uses separate control and data connections between the client and the server.[1] FTP users may authenticate themselves using a clear-text sign-in protocol, normally in the form of a username and password, but can connect anonymously if the server is configured to allow it. For secure transmission that hides (encrypts) the username and password, and encrypts the content, FTP is often secured with SSL/TLS ("FTPS"). SSH File Transfer Protocol ("SFTP") is sometimes also used instead, but is technologically different. History[edit] The original specification for the File Transfer Protocol was written by Abhay Bhushan and published as RFC 114 on 16 April 1971. Until 1980, FTP ran on NCP, the predecessor of TCP/IP.[2] The protocol was later replaced by a TCP/IP version, RFC 765 (June 1980) and RFC 959 (October 1985), the current specification.
Protocol overview[edit] Communication and data transfer[edit] ASCII mode: used for text. Login[edit] or: Hypertext. Text with references (links) to other text that the reader can immediately access "(...)'Hypertext' is a recent coinage. 'Hyper-' is used in the mathematical sense of extension and generality (as in 'hyperspace,' 'hypercube') rather than the medical sense of 'excessive' ('hyperactivity').
There is no implication about size— a hypertext could contain only 500 words or so. 'Hyper-' refers to structure and not size. " The English prefix "hyper-" comes from the Greek prefix "ὑπερ-" and means "over" or "beyond"; it has a common origin with the prefix "super-" which comes from Latin. It signifies the overcoming of the previous linear constraints of written text. The term "hypertext" is often used where the term "hypermedia" might seem appropriate. In 1992, author Ted Nelson – who coined both terms in 1963 [3][4]– wrote: Types and uses of hypertext [edit] Hypertext can be used to support very complex and dynamic systems of linking and cross-referencing. Academic conferences Hypertext conferences. Web page. A web page (or webpage) is a web document that is suitable for the World Wide Web and the web browser.
A web browser displays a web page on a monitor or mobile device. The web page is what displays, but the term also refers to a computer file, usually written in HTML or comparable markup language, whose main distinction is to provide hypertext that will navigate to other web pages via links. Web browsers coordinate web resources centered around the written web page, such as style sheets, scripts and images, to present the web page.
On a network, a web browser can retrieve a web page from a remote web server. On a higher level, the web server may restrict access to only a private network such as a corporate intranet or it provide access to the World Wide Web. On a lower level, the web browser uses the Hypertext Transfer Protocol (HTTP) to make such requests. Colour, typography, illustration, and interaction[edit] Dynamic behavior[edit] Browsers[edit] Elements[edit] Rendering[edit] URL[edit] HTML. HTML or HyperText Markup Language is the standard markup language used to create web pages. HTML is written in the form of HTML elements consisting of tags enclosed in angle brackets (like <html>).
HTML tags most commonly come in pairs like <h1>and </h1>, although some tags represent empty elements and so are unpaired, for example <img>. The first tag in a pair is the start tag, and the second tag is the end tag (they are also called opening tags and closing tags). The purpose of a web browser is to read HTML documents and compose them into visible or audible web pages. Web browsers can also refer to Cascading Style Sheets (CSS) to define the look and layout of text and other material.
History[edit] The historic logo made by the W3C Development[edit] In 1980, physicist Tim Berners-Lee, who was a contractor at CERN, proposed and prototyped ENQUIRE, a system for CERN researchers to use and share documents. Further development under the auspices of the IETF was stalled by competing interests. Browser Support Checklist CSS3 – Norman's Blog – Demos. Cascading Style Sheets. CSS is designed primarily to enable the separation of document content from document presentation, including elements such as the layout, colors, and fonts.[1] This separation can improve content accessibility, provide more flexibility and control in the specification of presentation characteristics, enable multiple pages to share formatting, and reduce complexity and repetition in the structural content (such as by allowing for tableless web design).
CSS can also allow the same markup page to be presented in different styles for different rendering methods, such as on-screen, in print, by voice (when read out by a speech-based browser or screen reader) and on Braille-based, tactile devices. It can also be used to allow the web page to display differently depending on the screen size or device on which it is being viewed. CSS specifies a priority scheme to determine which style rules apply if more than one rule matches against a particular element. Syntax[edit] Selector[edit] Use[edit] Web development. Web development is a broad term for the work involved in developing a web site for the Internet (World Wide Web) or an intranet (a private network). Web development can range from developing the simplest static single page of plain text to the most complex web-based internet applications, electronic businesses, and social network services.
A more comprehensive list of tasks to which web development commonly refers, may include web design, web content development, client liaison, client-side/server-side scripting, web server and network security configuration, and e-commerce development. Among web professionals, "web development" usually refers to the main non-design aspects of building web sites: writing markup and coding. For larger organizations and businesses, web development teams can consist of hundreds of people (web developers).
Web development as an industry[edit] Since the commercialization of the web, web development has been a growing industry. Typical areas[edit] Basic[edit] Server-side Programming. Most of the websites are created from static documents and image files. If you want to create an advanced website with forms handling, dynamically generated pages, shopping carts, content management systems, databases, and so on, you should learn a server-side programming language. The main difference between client-side and server-side programming is that client-side scripts are downloaded, interpreted and executed by the browser and the server-side scripts run on a server. The scripting and programming languages that are used to create server-side applications are: ASP, ASP.NET, PHP, JSP, ColdFusion, Ruby on Rails and more.
Asp (Active Server Pages) is a server-side scripting language created by Microsoft. Microsoft marketed ASP as an add on for IIS. ASP.NET is part of Microsoft .NET platform. PHP is a widely-used general-purpose scripting language that is especially suited for Web development and can be embedded into HTML. PHP. Scripting language created in 1994 PHP is a general-purpose scripting language geared towards web development.[8] It was originally created by Danish-Canadian programmer Rasmus Lerdorf in 1993 and released in 1995.[9][10] The PHP reference implementation is now produced by the PHP Group.[11] PHP was originally an abbreviation of Personal Home Page,[12][13] but it now stands for the recursive initialism PHP: Hypertext Preprocessor.[14] The standard PHP interpreter, powered by the Zend Engine, is free software released under the PHP License.
PHP has been widely ported and can be deployed on most web servers on a variety of operating systems and platforms.[17] The PHP language has evolved without a written formal specification or standard, with the original implementation acting as the de facto standard that other implementations aimed to follow. History[edit] Early history[edit] <! PHP/FI could be used to build simple, dynamic web applications. PHP 3 and 4[edit] PHP 5[edit] PHP 7[edit] PHP 8[edit] Client-side scripting. By viewing the file that contains the script, users may be able to see its source code. Many web authors learn how to write client-side scripts partly by examining the source code for other authors' scripts.
Due to security restrictions, client-side scripts may not be allowed to access the user's computer beyond the web browser application. Techniques like ActiveX controls can be used to sidestep this restriction. Client-side scripting is not inherently unsafe. Users, though, are encouraged to always keep their web browsers up-to-date to avoid exposing their computer and data to new vulnerabilities. List of Client-Side Scripting Languages[edit] References[edit] See also[edit] Server-side scripting. The Growing Importance of Client Side Programming | Grafx Design of Tampa. Web design and development is an ever-changing landscape with the core focus of attracting users. Whether those users are customers or subscribers, our goal as developers / designers is to captivate them and keep them on the site to do what we need them to do.
We have seen the web trends shift from simple forms and store fronts to complex websites with many options (that often confuse users). Basically the web is trying to find a balance to keep users happy while still giving them all the tools to get what they need done. With faster servers and internet connections we can do a lot more with sites than ever before but this does not necessarily translate into better sites.
This is where User Experience Design (UX) comes into play. Companies invest a lot of money in UX designers who can successfully orchestrate a web site or application to be both highly functional and highly usable and this is where client side programming is really taking off. Share and Enjoy. JavaScript_Handout_PF.pdf (application/pdf Object) UX design, service design and design thinking. Java applet. A Java applet that was created as supplementary demonstration material for a scientific publication.[1] Using applet for nontrivial animation illustrating biophysical topic (randomly moving ions pass through voltage gates)[3] Using a Java applet for computation - intensive visualization of the Mandelbrot set[4] Sufficient running speed is also utilized in applets for playing nontrivial computer games like chess[5] NASA World Wind (open source) is a second generation applet[6] that makes heavy use of OpenGL and on-demand data downloading to provide a detailed 3D map of the world.
Web access to the server console at the hardware level with the help of a Java applet Java applets run at very fast speeds comparable to, but generally slower than, other compiled languages such as C++. Overview[edit] HTML pages may embed parameters that are passed to the applet. Technical information[edit] Similar technologies[edit] Embedding into a web page[edit] Example[edit] <! A Java applet example Advantages[edit] Java: Java Applets. Java (programming language) Duke, the Java mascot Sun Microsystems released the first public implementation as Java 1.0 in 1995.[1] It promised "Write Once, Run Anywhere" (WORA), providing no-cost run-times on popular platforms.
Fairly secure and featuring configurable security, it allowed network- and file-access restrictions. Major web browsers soon incorporated the ability to run Java applets within web pages, and Java quickly became popular. With the advent of Java 2 (released initially as J2SE 1.2 in December 1998 – 1999), new versions had multiple configurations built for different types of platforms. For example, J2EE targeted enterprise applications and the greatly stripped-down version J2ME for mobile applications (Mobile Java).
J2SE designated the Standard Edition. On November 13, 2006, Sun released much of Java as free and open source software, (FOSS), under the terms of the GNU General Public License (GPL). There were five primary goals in the creation of the Java language:[23] Installer les outils de développement - Java. Web Services explained. REST (Representational state transfer) Implementing REST Web Services: Best Practices and Guidelines. RapportSOAP.pdf (application/pdf Object) XML background. Web Services Description Language.