A user interface must display information to the user. In addition, a user interface must also allow the user to input data such as text or numbers. Finally, a user interface must allow the user to control the app. Displaying data, accepting data, and accepting commands form the heart of any user interface.
The three most common types of user interface objects are
Labels
Text fields
Buttons
Labels simply display text. Text fields can display text but are most often used to allow the user to type in text. Buttons can also display text (usually the name of the command ...
