Exercises 
2.1
1- Java is a portable program.
2- Java is easier to use and learn, less errorprone, more portable, and better suited to the Internet compared to C++.
3- A thread is a process that can run cocurrently with other processes. Well one thread transfers an image from one machine to another across a network, while the other thread simultaneously interacts with the user.
2.2
1- JVM stands for Java Virtual Machine.
2- Byte Code is the machine language for an imaginary Java compuiter. You have to install JVM to a computer to use a byte code.
3- Applets run in a JVM that is incorporated into your Web browser. Applets are small Java programs already translated into byte code.
2.4
1- Program is a set of instructions that tells the machine what to do.
2- Println is the name of the message being sent to the system.out.
3- System.out is used before each statement you want.
4- HAVE TO DO ON JAVA
2.5
1- Edit, Compile, and Execute are three steps in writing and running a program.
2- Compile- time errors are mistakes detected by the compiler.
3- a. System.out.println("Here is an error)    
   Correct a-  you need quotations after error and before paranthesis
   b. System.out.println("Here is another error";
   Correct b- You need a ending paranthesis after the quotation mare and before the semi-colon.
4- If it is not easily readable then it is harder to change information and harder on users.
2.7
1- A. White
2- Frame respnds to messages and fixes problems.
   Panel displays other objects such as geometrical shapes.
   Layout manager places the adding of objects in a container.
4- HAVE TO DO ON JAVA