shabeer b asked:
User-centered design (UCD) is an approach for employing usability. It is a structured product development methodology that involves users throughout all stages of Web site development, in order to create a Web site that meets users’ needs. This approach considers an organization’s business objectives and the user’s needs, limitations, and preferences.
User-centered design (UCD) is an approach for employing usability. It is a structured product development methodology that involves users throughout all stages of Web site development, in order to create a Web site that meets users’ needs. This approach considers an organization’s business objectives and the user’s needs, limitations, and preferences.
UI
Usability measures the quality of a user’s experience when interacting with a product or system—whether a Web site, a software application, mobile technology, or any user-operated device.
Andre

Herman
Hhhmm… You just answered your own question.
But it’s too long. To shorten it:
User-Centered Design – The system is designed specifically for ‘that’ user. So if other people uses the system, they’ll less like to understand it easily compare to the person the system is designed for.
UI – User Interface such as buttons, knobs, sliders, etc. It is something the user use to interact with the system.
Comment by Eff — August 12, 2010 @ 8:18 pm