Oracle Certified Associate, Java SE 7 Programmer Study Guide

import statement indicates which packages and classes are used by the class. This allows the compiler to determine whether the package's members are used correctly

Packages provide a means of grouping similar classes, interfaces, enumerations, and exceptions together.

Applets are normally embedded within an HTML page and offer a means of achieving client-side execution of a code. It does not have a main method but uses a series of callback methods used by the browser to manage the application