Color, typography, illustration and interaction

Web pages usually include information as to the colors of text and backgrounds and very often also contain links to images and sometimes other media to be included in the final view.

Layout, typographic and color-scheme information is provided by Cascading Style Sheet (CSS) instructions, which can either be embedded in the HTML or can be provided by a separate file, which is referenced from within the HTML. The latter case is especially relevant where one lengthy stylesheet is relevant to a whole website: due to the way HTTP works, the browser will only download it once from the web server and use the cached copy for the whole site.

Images are stored on the web server as separate files, but again HTTP allows for the fact that once a web page is downloaded to a browser, it is quite likely that related files such as images and stylesheets will be requested as it is processed. pagina web An HTTP 1.1 web server will maintain a connection with the browser until all related resources have been requested and provided. Browsers usually render images along with the text and other material on the displayed web page.

Dynamic behavior

Client-side computer code such as JavaScript or code implementing Ajax techniques can be provided either embedded in the HTML of a web page or, like CSS stylesheets, as separate, linked downloads specified in the HTML. These scripts may run on the client computer, if the user allows them to, and can provide additional functionality for the user after the page has downloaded.

Browsers

A web browser can have a Graphical User Interface, like Internet Explorer, Mozilla Firefox and Opera, or can be text-based, like Lynx.

Web users with disabilities often use assistive technologies and adaptive strategies to access paginas web. Users may be color blind, may or may not want to use a mouse perhaps due to repetitive stress injury or motor-neurone problems, may be deaf and require audio to be captioned, may be blind and using a screen reader or braille display, may need screen magnification, etc.

Disabled and able-bodied users may disable the download and viewing of images and other media, to save time, network bandwidth or merely to simplify their browsing experience. Users of mobile devices often have restricted displays and bandwidth. Anyone may prefer not to use the fonts, font sizes, styles and color schemes selected by the web page designer and may apply their own CSS styling to the page.

The World Wide Web Consortium (W3C) and Web Accessibility Initiative (WAI) recommend that all web pages should be designed with all of these options in mind.

Rendering

Web pages will often require more screen space than is available for a particular display resolution. Most modern browsers will place scrollbars (the bar at the side of the screen that allows you to move down) in the window to allow the user to see all content diseño paginas web. Scrolling horizontally is less prevalent than vertical scrolling, not only because those pages do not print properly, but because it inconveniences the user more so than vertical scrolling would (because lines are horizontal; scrolling back and forth for every line is much more inconvenient than scrolling after reading a whole screen; also most computer keyboards have page up and down keys, and many computer mice have vertical scroll wheels, but the horizontal scrolling equivalents are rare).

When web pages are stored in a common directory of a web server, they become a website. A website will typically contain a group of web pages that are linked together, or have some other coherent method of navigation. The most important web page to have on a website is the index page. Depending on the web server settings, this index page can have many different names, but the most common is index.html. When a browser visits the homepage for a website, or any URL pointing to a directory rather than a specific file, the web server will serve the index page to the requesting browser. If no index page is defined in the configuration, or no such file exists on the server, either an error or directory listing will be served to the browser.

A web page can either be a single HTML file, or made up of several HTML files using frames or Server Side Includes (SSIs). Frames have been known to cause problems with web accessibility, copyright, navigation, printing and search engine rankings, and are now less often used than they were in the 1990s. Both frames and SSIs allow certain content which appears on many pages, such as page navigation or page headers, to be repeated without duplicating the HTML in many files. Frames and the W3C recommended alternative of 2000, the <object> tag, also allow some content to remain in one place while other content can be scrolled using conventional scrollbars. Modern CSS and JavaScript client-side techniques can also achieve all of these goals and more.

When creating a web page, it is important to ensure it conforms to the World Wide Web Consortium (W3C) standards for HTML, CSS, XML and other standards. The W3C standards are in place to ensure all browsers which conform to their standards can display identical content without any special consideration for proprietary rendering techniques. A properly coded web page is going to be accessible to many different browsers old and new alike, display resolutions, as well as those users with audio or visual impairments.

Viewing a web page

In order to graphically display a web page, a web browser is needed. This is a type of software that can retrieve web pages from the Internet. Most current web browsers include the ability to view the source code. Viewing a web page in a text editor will also display the source code, not the visual product.

In truth, Linus Torvalds was quite simply unwilling to name his new operating system Linux - he was of the opinion that it was arrogant. At this point, work on the GNU Project, an undertaking making an attempt to write a free Unix-compatible operating system, had been under way for almost ten years but Torvalds was unwilling to wait any longer. In 1992, a mere year after Linux was released, it was announced “obsolete” by the creator of MINIX, Andrew Tanenbaum. He cited its lack of portability and its ties to specific hardware as the main reasons that Linux would die out in the next couple of years.

With the release of the GNU project, Tanenbaum was shown to be completely wrong. Collaborating
with GNU developers, Torvalds encapsulated the code into his program and made a fully-functional, portable operating system. Best of all, it was free and the code open-source.

Over time, programmers have authored a variety of flavours based entirely on the Linux kernel. The most popular home distributions, Debian, GNOME and KDE all work a little differently, yet all supply a graphical user interface on top of the shell. This means that users are able to do more or less anything without ever having to come face-to-face with the command-line.

In 1994, the first commercial Linux company, Red Hat, was launched and was the first Linux distribution to employ a package manager. In bundling a few software options with the distribution, Red Hat gave users a simple way to install the required software. With the code for the Linux kernel openly available for programmers to change and build on, it provides a world of possibilities. End-users who wish to have the freedom to work in a command-line environment now have an operating system with which to work and those preferring a graphical interface can build on the kernel to form one. Its cost-effectiveness and robustness has made it entirely viable to be used as an operating system for servers.

Linux as a server operating system has proved an obvious choice for web site hosting and has proved a thoroughly credible
platform for the growing web site design industry. In an environment where unreliability is not at all popular Linux is in very many cases seen as the platform of choice. On the desktop in offices, schools and factories the wide availability of software has led to wide-spread uptake. Municipalities the world over are making significant savings by employing Linux on their computer network over their substantial user base. Without a doubt, Linux has truly come of age.