HTML URL's

From http://www.w3schools.com (Copyright Refsnes Data)

# HTML Uniform Resource Locators

## HTML Links

When you click on a link in an HTML document like this: Last Page, an underlying <a> tag points to a place (an address) on the Web with an href attribute value like this: <a href="lastpage.htm">Last Page</a>.

The Last Page link in the example is a link that is relative to the Web site that you are browsing, and your browser will construct a full Web address like http://www.w3schools.com/html/lastpage.htm to access the page.

## Uniform Resource Locators

Something called a Uniform Resource Locator (URL) is used to address a document (or other data) on the World Wide Web. A full Web address like this: http://www.w3schools.com/html/lastpage.htm follows these syntax rules:

scheme`://`host.domain`:`port`/`path`/`filename

The scheme is defining the type of Internet service. The most common type is http.

The domain is defining the Internet domain name like w3schools.com.

The host is defining the domain host. If omitted, the default host for http is www.

The :port is defining the port number at the host. The port number is normally omitted. The default port number for http is 80.

The path is defining a path (a sub directory) at the server. If the path is omitted, the resource (the document) must be located at the root directory of the Web site.

The filename is defining the name of a document. The default filename might be default.asp, or index.html or something else depending on the settings of the Web server.

## URL Schemes

Some examples of the most common schemes can be found below:

Schemes | Access
--- | ---
file | a file on your local PC
ftp | a file on an FTP server
http | a file on a World Wide Web Server
gopher | a file on a Gopher server
news | a Usenet newsgroup
telnet | a Telnet connection
WAIS | a file on a WAIS server

## Accessing a Newsgroup

The following HTML code:

<a href="news:alt.html">HTML Newsgroup</a>

creates a link to a newsgroup like this HTML Newsgroup.

## Downloading with FTP

The following HTML code:

<a href="ftp://www.w3schools.com/ftp/winzip.exe">Download WinZip</a>

creates a link to download a file like this: Download WinZip.

(The link doesn't work. Don't try it. It is just an example. W3Schools doesn't really have an ftp directory.)

## Link to your Mail system

The following HTML code:

<a href="mailto:someone@w3schools.com">someone@w3schools.com</a>

creates a link to your own mail system like this:

someone@w3schools.com

From http://www.w3schools.com (Copyright Refsnes Data)