2. import - statement to locate classes required to compile a java program.

3. showMessageDialog - part of class JOptionPane. It shows the messages in a dialogue box with the result of an arguments.

4. Integer.parseInt - converts its String argument to an integer. Supposing you enter in a dialogue box a number then you can you this tag to convert it to integer.

2. println - of the System.out displays a line of information in the command window.

3. System.out.print - does not position to the beginning of the next line in the command window when it finishes displaying its argument. The next character that is displayed in the command window will appear immediately after the last character displayed with System.out.print.

1. Access Modifier - specifies the circumstances in which the class can be accessed. Example is public which indicates that this code can be accessed by all objects or can be extended, or used as a basis for another class. If public is omitted then you limit it only for this class. Access Modifier is followed by the word class.

2. Class Name - Example is public class XXX. The class name here is XXX which is a name assigned by you. It should be user-friendly word that is not on the list of reserved words, contain no spaces and must not begin with number.
Example:
Record123 (good) Record 123 (bad with space)
Employ 123data (bad begin with numbers)

3. public static void main ( String args[] ) - is a part of every Java application.
A. Paranthesis after main - indicate that main is a program building block called a method.
B. void - indicate that this method will perform a task but will not return any information when it completes its task.