"modal" in apple documentation

Apple uses "modal" often in their documentation. Like dismissModalViewController in their titles of methods, or documentation like:

"The UIViewController class provides the fundamental view-management model for iPhone applications. The basic view controller class supports the presentation of an associated view in addition to basic support for managing modal views and rotating views in response to device orientation changes. Subclasses such as UINavigationController and UITabBarControlle开发者_运维技巧r provide additional behavior for managing complex hierarchies of view controllers and views."

I'm not sure as to what context I should think of when I see modal in the names and documentation. Any thoughts? Thanks.

"Modality" is a UI concept. It derives from the word "mode", as in "to put an application in some particular mode". It refers to the idea that "modal" views/actions/behaviors, when they occur, change or restrict the set of things the user can do and interact with.

You hear this term now mostly to refer to UI views which essentially pop-over or block the "normal" baseline UI with some special dialog or window. In UIKit, alert boxes are modal-- you can't do anything else with an application until you dismiss them. Action sheets are like this too. The iPhone SDK lets you present view controllers as modal also, but the semantics are nearly lost; it really mainly just refers to how the user perceives them-- they slide up from the bottom, temporarily obscuring whatever the UI below them was.