Let’s define some terms that we will use frequently.
A computer program is a list of instructions that tell a computer what to do. Computer programs are stored in files on a computer's hard drive.
A programming language is a set of rules to convert words into computer
programs. Java is a programming language that has a different set of rules than
other programming languages.
A compiler is a computer program that interprets files containing a
programming language. The Java compiler interprets files containing the Java
programming language and produces bytecode.
Bytecode refers to general computer instructions which are not associated with
any particular computer.
A microprocessor is a hardware inside a computer that executes instructions and
does all the work of your computer program.
The Java Virtual Machine (JVM) is a program which converts bytecode into
instructions that the microprocessor can execute.
Your First Java Program "HelloWorld"
When learning a new programming language, the first task is normally to write a program that simply prints the words “Hello World” to your computer’s
display. Once we have written, compiled, and executed the program, and verified
that “Hello World” appears on the display, we have successfully run the
HelloWorld program.
