Java is a high-level programming language developed by Sun Microsystems . Although it was originally designed to develope programs for set-top boxes and handheld devices, but it later became quite popular for making web applications.
For example, most Java programs have classes that are used to define objects and methods, which are then assigned to individual classes.
Java is much more strict than C ++, which means that variables and functions must be explicitly defined in it. Which means that Java source code produces more errors or “exceptions” than other languages. But it also limits other types of errors that are generated by undefined variables or unassigned types.
Unlike Windows executables (.EXE files) or Macintosh applications (.APP files), Java programs are not run directly by the operating system , but Java programs are interpreted by the Java Virtual Machine , or JVM, which Runs across multiple platforms.
This means that all Java programs are multiplatform and can run on different platforms including Macintosh, Windows, and Unix computers. But to run Java applications or applets, JVM must be installed.
There is also a good thing, JVM is included on the part of Java Runtime Environment (JRE), which is available for a free download.
NOTE Oracle acquired Sun Microsystems in January, 2010. Therefore Java is now maintained and distributed by Oracle.