Web page
From Freepedia
A Web page or webpage is a "page" of the World Wide Web, usually in HTML/XHTML format (the file extensions are typically htm or html) and with hypertext links to enable navigation from one page or section to another. Web pages often use associated graphics files to provide illustration, and these too can be clickable links. A web page is displayed using a web browser.
A web page can contain any of the following:
- Text
- graphics (gif, jpeg or png)
- Audio (.mid or .wav)
- Interactive multimedia content that requires a plugin such as Flash, Shockwave or VML
- applets (subprograms that run inside the page)which often provide motion graphics, interaction, and sound
Web pages also contain content that cannot be seen in the browser:
- Scripts (usually JavaScript) which add functionality to the page - e.g. powering rollover effects or verifying form input.
- Meta tags - hidden content with information about the page, instructions for search engine robots, etc. The keywords and description meta tags help search engines categorise the page and provide information for search results.
- CSS Stylesheets which determine how the page is formatted
- Comments
Web pages can be larger than the web browser window. They are often taller than the browser window and require vertical scrolling. Pages often have additional content on the right which is not visible in smaller windows without horizontal scrolling. Pages designed to scroll horizontally are less common, partly because they do not print out well, but can be used to good effect for galleries or to add interest to a site. See also page widening.
A web page can be either a single page, or a frameset made up of separate pages (frames). Each frame contains an HTML page. Frames can cause problems with navigation and printing and unless expertly handled can adversely affect search engine ratings. Their main merit is to allow some content (usually a naviagation menu) to stay in one place while other content is scrolled.
A collection of web pages stored in a single folder or within related subfolders of a web server is known as a website. A website includes an index page. This is a file called index.htm, index.html, index.php, index.asp etc. When you type in a web address URL which doesn't include a page (e.g. www.mysite.com) the web server will look for an index page and serve that to your browser. If no index page exisits, you will see either a listing of the folder's contents, or an error page (usually 'permission denied').
A consideration in designing and testing web pages is that they should be suitable for many browsers and browser settings and different screen resolutions, as well as accessible to people with disabilities (e.g. sight impairment), older browsers and text-only browsers. Target audience, budget and lack of awareness of accessibility issues often mean that a site is not as acessible as it could be. Using features which only work in one browser without providing alternative content is considered bad practice; the W3C works with browser manufacturers to develop web standards and encourage standards compliance.
Contents |
Navigation bar
A navigation bar, linkbar, link bar or links bar is an area/a pane of a web page that contains hypertext links in order to enable navigation from one page of a website to another.
URL
Usually a web page has a more or less permanent URL, a permalink, and therefore allows deep linking. Sometimes it has only a temporary URL referring to a cache area. This may e.g. be the case when the page is the result of zooming and shifting a map. Sometimes a page results from a web page by some action, e.g. replacing the content of one of the frames, while the new page does not have its own URL. Perhaps such a page, as well as a page with a form field filled in, strictly can not be called a web page, because it is not on the web, but created from what is on the web.
Graphics
For embedding (transclusion) of an image in a web page, see HTML element#Images.
The graphics file format in web pages is usually JPEG for photographs and GIF or PNG for other images such as diagrams, drawings, graphs, etc. The last two formats can also be used for photographs but are not as suitable for that purpose as JPEG (JPEG is lossy while GIF and PNG are lossless). GIF is used for animations, GIF and PNG for images with transparent pixels, PNG for images with partially transparent pixels (but this is not supported by e.g. IE). All these are raster graphics. There is also the SVG format: Scalable Vector Graphics. Currently more common ways to supply vector graphics are either with a PDF file, viewed either using a plug-in of the browser or a separate viewer, or with Flash. This is useful e.g. for a map, often a combination of a vector graphics layer and text, and possibly a raster graphics layer. This gives better results when zooming in than a GIF or PNG image (JPEG would be even worse due to compression artifacts).
Alternatively, on zooming in the server supplies a new image. In that case one can not download the whole map, unless perhaps piece by piece. See e.g. the links in Map#External links.
Also, as an example, compare the GIF and PDF province maps in South Holland#External links.
See also Map#Electronic maps.
Viewing a web page
Since most web pages are mostly text, you can view them in any application that can read text documents. However, to view a web page, as it is intended, one needs a type of software known as a user agent or better still a web browser, which is a piece of software specifically designed to view web pages. There are many different types of web browsers available with various capabilities and a wide range of supported platforms.
Creating a web page
To create a web page, one needs a general text editor or a special HTML editor like Microsoft FrontPage, Macromedia Dreamweaver, Mozilla Composer and so on, and a FTP program to upload the page to the web server. One can use the web browser to upload the web page file to the server, but that is not recommended.
One can also use a pre-made web template to create a web page. Web Templates let web page designers edit the content of a web page without having to worry about the overall asthetics.
Wiki is a special way to create or modify and upload web pages without FTP-ing or upload file, only filling a text form in a web page. Wikipedia is an example of wiki technology.
Saving a web page
When saving a local copy of a web page, the web browser usually allows a choice between:
- saving the rendered text without formatting or images, and without indicating which words are links or what their destination is
- saving the HTML-file without changes, without images (view the source and save that)
- saving the HTML-file, changing relative links to absolute ones, without images
- also saving the images and adjusting the references to them accordingly; either a separate folder is made (IE, Mozilla) or the same is used (Opera);
- saving the HTML-file including all images, stylesheets, scripts etc. to a single .MHT file. This is support by Internet Explorer, Mozilla and Mozilla Firefox (the last two only if the Maf plugin has been installed). An .MHT file is based upon the MHTML standard.
The common web browsers, like Mozilla, Mozilla Firefox and Internet Explorer, also allow you to print the currently viewed web page or optionally "print" to a file which can later be viewed or printed. This has an advantage in that some web pages are specially designed using Cascading Style Sheets, or a separately generated page, to show both the text and target destination of links contained within the web page. Likewise any images are contained within the single file.
For a short page another possibility is saving a screenshot (only useful in special cases). This shows links, but not their destination.
