View source for Notes from layout video

The gui components are called widgets or views<br>
They arranged according to a layout, LinearLayout(Vertical) LinearLayout(Horizontal)<br>
Layouts are in fact views themselves<br>
RelativeLayout, needs an '''align'''<br>
There are actions and events<br>
An application can comprise multiple activities and screens, each one has identifier<br>
Back button on phone returns one to the previous activity<br>
A pop up messages is "toast"<br>