Objectives of this Tutorial
Generally: To create different kinds of hyperlink to connect web pages.
Specifically: On completion of this lesson you will be able to:
- Add text and image hyperlinks to web pages
- Follow a hyperlink
- Edit and delete a hyperlink
- Create a hotspot (clickable imagemap)
What is a Hyperlink
A hyperlink connects one resource to another. When the user clicks the link, the new resource is opened. A link can point to a different part of the current page, another web page in the same web, a web page in a different web, a file of a different type (such as an Excel spreadsheet or Adobe Acrobat document) or to an email address.
The hyperlink can be embedded in text (hypertext) or a picture. To be effective, the text or picture should indicate where the link goes. For example, a text hyperlink from the phrase "What's new in Microsoft FrontPage 2002" and a picture hyperlink from the Microsoft FrontPage logo both would indicate that the hyperlink goes to a page describing new features in FrontPage 2002.
Web browsers usually underline text hyperlinks by underlining them and displaying them in a specific colour. Hyperlinks in pictures are invisible. However, users can tell when the pointer is over a hyperlink because it changes to a pointing hand .
Uniform Resource Locators (URL)
To connect to a resource, a hyperlink must point to the resource's URL. In FrontPage, it is easy to create hyperlinks without having to understand URLs. However, you may find it worthwhile to know what is going on "in the background" when you create a link.
Every resource (email service, web page, internet chat room and so on) on the internet has an address that allows other computers to connect to it. This is address is called a Uniform Resource Locator.
Each resource is hosted by a server, which is identified to other computers by its IP address number and the service's port number. An IP address number consists of four decimal bytes (a number ranging from 0 to 255) separated by dots (for example, 188.8.131.52). A port number is like a broadcast channel for particular types of service (web pages, email, ftp and so on).
The numerical internet address understood by computers is quite incomprehensible to most people. For this reason a system of identifying servers using a domain name (or host name) was developed. An internet domain name consists of the name itself (usually the name of the company or organisation) and one or more suffixes (such as .COM or .CO.UK) used as categories.
A website can be accessed by typing a domain name (such as www.courseware.co.uk) into the Address bar. This will open the website's default page (or home page).
This is a shorthand way of accessing a website however. Every single document and service on the internet has a unique address, called a Uniform Resource Locator (URL). The domain name is only part of this address.
A URL contains all the information needed by a web browser to get a specific document from a server. The information required is as follows:
- The type of service that should be used to get the data and consequently the port number of the service.
- The name and location of the host computer (server) storing the document - the domain name.
- The location of the file on the host computer.
Make up of a web address
For example, consider the following URL:
The above URL begins with the letters http. This means that the documents are served by a HyperText Transfer Protocol (HTTP) server. The URLs for web pages usually start with this (though you will also see HTTPS(ecure), which indicates a secure web server, used for e-commerce). Most URLs do not specify the port number of the service, as common services are always found on the same port number (for example, HTTP is always on port number 80).
:// - means that the next part of the URL is the name and location of the server. This group of characters is called a separator. Separators are used to indicate to the computer processing the URL that one part of the URL has ended and the next part is coming.
www.courseware.co.uk is the domain name of the server. When a web browser requests a URL, the domain name gets translated into an IP number, which is then used to find the server on the internet, by looking up the domain name on a database. Domain names make it easier for people to remember URLs. They also make it easier to move a website from one server to another without having to tell everyone that the address has changed - you only have to change the number in the database.
Domain names contain some standard notations. For example, www identifies the service as being on the world wide web. .co identifies the website as a commercial organisation. It is convention that commercial sites use co or com, academic URLs have ac or edu (for academic or education) and governmental or non-profit organisations use org. .uk indicates that the site is based in the UK. These suffixes are created and controlled by internet organisations.
The URL up to now has identified where to look for the web page on the internet. The rest of the URL describes where on the server the page is located. This part of the URL is like the path and file names you see in Microsoft Windows, except that forward slashes (/) are used to separate folder and file names rather than backslashes (\) and there is no need to identify the disk drive.
about/contact.htm indicates that the Contact web page (HTML page) is located in the About subfolder of the server's web folder.
Relative path URLs
When you create a link to a page within a web, you can use a relative URL. A relative URL contains just enough information to find the file from the current file.
For example, to link to the contact.htm page from the web's home page, the relative URL would be about\contact.htm. To link to the home page from the contact.htm page, the link would be ..<b>index.htm (.. means "go up one folder").
Other types of URL
URLs are also used to access other resources on the internet, including email addresses and File Transfer Protocol (a system for sending files over the internet).