The purpose of web.

Designing for the web means designing sympathetically with the way people actually use the web. In this section looks at the discipline of web design, how to approach design as a job, and introduces some mental techniques for increasing enjoyment and achievement.
People approach web sites in very different ways to how we design them
They skim pages for clues, instead of reading
They make snap decisions, instead of evaluating and judging carefully
They might not even be looking at the complete picture
They are driven by their goals, not ours

Designers need special skills to succeed in this environment
We must gain the best possible insight into our users' goals, so that we can help achieve them.
We must get clear on our design's purpose, and have the mental discipline to stick to it
We must pursue simplicity ruthlessly - if an element adds complexity but not value, it must be changed

Goal-Oriented Design

Goal-Oriented Design is critical factor in the success of any design project, You must learn techniques that help you realize your own goals and gain insight into what your target audience really wants.

All web sites are built in response to many needs
Your site may have information that people want, you may have information that you want them to have that they don't necessarily want, or you may want to get information for them. Your site may be a way to pass the information between different consumers & Buyer.
It's really important to understand that all kinds of web sites try to resolve various needs. The publisher must have a need which drives them to publish. The site's visitors must have a need (to earn money, to succeed at their work, to be entertained).
Behind all these needs are goals that drive our desires and behaviour. It's our goals that drive us to use web sites, to buy products and use services.