User interface design focuses on creating a simple, structured, and visible interface that provides feedback and tolerance for errors. The dynamic aspects like feel and static aspects like look aim to optimize the user's experience and minimize the time spent interacting with software and websites by following how people naturally work rather than strict standards.

1. Principles & Techniques

2. User interface design is the design focused on the user's
experience and interaction with software applications
and websites.
UI, how it should be…

3. Design must follow People’s own standards to get things
done rather than the so called web standards.
Standards are vital, but interfaces has got the priority.

4. Simplicity
Structure
Visibility
Feedback
Tolerance
Reuse
and demands least user time.

5. Dynamic aspects of the interface is often referred as
the "feel" of the interface.
The represent
the static aspects of the interface is regarded as the
"look" of the interface.

6. nettuts.com
wikipedia.org