UIView

A UIView represents a rectangular area of the screen that can hold UITextFields, UIButtons, UIImages, etc.
You would generally create a UIView in a UIViewController's loadView method.

Example
UIView *myView =
   [ [UIView alloc]
   initWithFrame:[[UIScreen mainScreen]
   applicationFrame] ];

self.view = myView;
[myView release];

Displaying new views:
MyController *controller =
    [[MyController alloc] init];

[self presentModalViewController:controller
    animated:YES];

[controller release];



and to dismiss the controller:
[self dismissModalViewControllerAnimated:YES];



or use a UINavigational controller

[self.navigationController
    pushViewController:myController
    animated:YES];

[[self navigationController]
    popViewControllerAnimated:YES];