Dictionary

The type Dictionary is used to describe a plain JavaScript object used to pass a set of properties.

The type Dictionary< Type > is used to describe a dictionary where the properties correspond to the properties of the named Type. So Dictionary< Titanium.UI.Window > refers to a dictionary of Window properties.

Property dictionaries are used extensively in the Titanium API, especially when creating objects. For example, You can specify the initial properties for a new window by passing a Dictionary< Titanium.UI.Window > object to the createWindow method:

var window = Ti.UI.createWindow({
    title: "Test", 
    fullscreen: true, 
    backgroundColor: '#aea'
});