Online vs print

The online world (often referred to as New Media) is fundamentally different to print or video in how it is used. By understanding the differences, you can adopt a different approach when writing for the web.
The four main reasons why the online world is different from the print one are:
Non-linear
Non-dimensional (it's in cyberspace)
Interactive
Multimedia
Non-linear
Print writing is almost always linear (Oxford dictionary defines this as “arranged in or extending along a straight line; involving one dimension only; sequential). There is a start (the contents page) the middle (chapters) and finish (conclusion).
The web however is non-linear because it uses hyperlinks. This means that you can select a link that appears to interest you and go to a page which may be totally unconnected with the site you came from. Your movements can be from random and indiscriminate to cognitive and intuitive. If the content is organised correctly, the links on offer will let you follow a logical path. However, you are under no obligation to do so!
In fact, in the online world, there is no beginning or an ending. You can enter any page by selecting its link from a totally different website and it may still be of great value to you!
An extension of hyperlinks is hypermedia which will include additional components such as two dimensional and three dimensional structured graphics, paint graphics, spreadsheets, video, sound, and animation.
Non-dimensional
Online is non-dimensional because it’s “virtual” and does not exist in real space. In contrast, a book or newspaper exists in three dimensions. You can touch it, feel it, assess its size and thumb through it to see what information it contains. You cannot do this online.
Print is also portable in that you can take a book with you on holiday, on the plane or train journey to work. You can read it on a beach or by the swimming pool. Online content can only be accessed on screen. With the increased use of laptops, online content has become more portable than before, but the distinction still exists.
The non-dimensional nature of online content is entirely consistent with its non-linear nature. The user does not have to rely on a table of contents or index page to get to the page that interests them. This is especially true with the increased use of search engines for content.
Interactive
Online is interactive because the user makes the decision about which links to follow and which to ignore. The mouse in your hand gives you control over the entire website and indeed the entire cyberspace! The experience you have will depend on your next click (always assuming that your next click is developed by a competent person!).
The various forms of interaction are growing as the web environment becomes more sophisticated. From filling in forms, querying search engines and databases, taking part in forums and real time chat, feedback, watching movies through to listening to music. The choice is yours.
This range of interaction is not possible with print. The most you can do is pick it up and turn over a page.
Multimedia
The interactivity of the online world increases with the use of various forms of multimedia. This is where text, graphics, animation, audio and video are used in an integrated way. Content editors now need to consider not only the words they use, but also the elements of multimedia they use to enhance the user experience.
It is said that “a picture is worth a thousand words” (in-fact the original Chinese proverb translates to “a picture's meaning can express ten thousand words”). The correct combined use of text and graphics can enhance the users understanding and remembering of the message.
If a picture is worth a thousand words, then a moving one must be worth a million! This is the power of animated pictures. From the simple animated GIF (set of slides which have each been given a length of time to display and can repeat as many times as you like, but have no sound track), rollover images, Flash files through to Web Three dimensional applications like VRML.
Virtually all computers now have sound cards as standard. This now increases the opportunity to integrate audio files with other forms of media to provide a really powerful user experience.
Finally, an extension of audio is video files. There are numerous ways to create, edit and distribute video. As with audio, some formats are designed for streaming and others are not.