All AWT components begin with java.awt. This is merely a typing reduction mechanism. The two prefixes supported now are java.awt and com.sun.java.swing. This is the Java component you wish to use in the interface for the particular class. In this case a Frame is desired.
Frames are separate windows that can be moved, iconified and destroyed.
This line also has a comment. Style comments look just like C or Java comments. A Frame is a container and therefore has a layout. If no layout is specified the default is FlowLayout. Here, we want a BorderLayout because we only have two elements and one is below the other.