User interface design

Please explain the role of operating systems, web browsers, and other technologies for user interface design. Don't need a long explanation of the terms just need a short one. Thank you for any answer you give.

The operating system (OS) of a computer is code that provides an environment for managing the hardware in a way that allows software developers to provide solutions for many problems. In an object oriented system, the OS provides many tools like text boxes, picture boxes and command buttons (the objects) and each of those have "properties;" a set of values that describe how the object looks and reacts to the user's input. They also have "Methods" which are segments of code that can be run from other parts of the program and "Events;" code that can be called when a certain condition is met.

Development environments like Visual Basic or C++ also have access to OS components that can be used in their projects like the Common Dialog control that accesses files and printers or browsers, email clients or communication controls that can be built into projects.

More simply, the operating system is a program that loads when you switch the computer on. It handles the passing of information between the different parts of the computer.

Any software that is to run on that computer has to be able to run in the environment created by that operating system. This means that programs written for one operating system may not work on another.

Web browsers simply translate the HTML and Javascript code that is passed to them from servers by part of the operating system that handles the link to the internet. The result is the text and graphics that display on your screen.

There are various languages that generate this HTML and Javascript. The manner in which the user navigates the screen is usually by the browser recognising the use of arrows keys, page up and page down etc. The change of a page is either down using hyperlinks or javascript commands.

Good user interfaces offer the means for disabled users to run screen handling software (so that the computer can speak it or display it in a better way for them) that picks up certain additional code that really should have been programmed into the HTML.