A change of context includes changes of:
A) User agent (Software that retrieves and presents content, e.g., a Web browser, media player, plug-in or other program including assistive technologies. A completely separate user agent, such as an external viewer programme, opens.)
B) Viewport (Content is rendered in one or more viewports. These include browser windows, browser tabs, frames, loudspeakers, and virtual magnifying glasses. Typically, a new window opens.)
C) Focus (Focus refers to which interactive control on the screen -- a link, form control, button, or custom control -- currently receives input from the keyboard (and from the clipboard when you paste content). The user's focus moves unexpectedly to a different part of the current Web page.)
D) Content that changes the meaning of the Web page (This includes significantly re-arranging the content of a page.)