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Question 21 :

What is Java Platform ?

Answer :

Consists of class libraries, a Java virtual machine (JVM) and class loader (which comprise the runtime environment) and a compiler, debugger and other tools (which comprise the development kit). In addition, the runtime platform is subject to a set of compatibility requirements to ensure consistent and compatible implementations. Implementations that meet the compatibility requirements may qualify for Sun's targeted compatibility brands. Java 2 is the current generation of the Java Platform.


Question 22 :

What is Java Platform Editions ?

Answer :

A Java platform "edition" is a definitive and agreed-upon version of the Java platform that provides the functionality needed over a broad market segment. An edition is comprised of two kinds of API sets: (i) "core packages," which are essential to all implementations of a given platform edition, and (ii) "optional packages," which are available for a given platform edition and which may be supported in a compatible implementation.

There are 3 distinct editions of the Java Platform:
* Java 2 Platform, Enterprise Edition:
The edition of the Java platform that is targeted at enterprises to enable development, deployment, and management of multi-tier server-centric applications.
* Java 2 Platform, Micro Edition:
The edition of the Java platform that is targeted at small, standalone or connectable consumer and embedded devices to enable development, deployment, and management of applications that can scale from smart cards through mobile devices and set-top boxes to conventional computing devices.
* Java 2 Platform, Standard Edition:
The edition of the Java platform that enables development, deployment, and management of cross-platform, general-purpose applications.


Question 23 :

What is Java Remote Method Invocation (RMI) ?

Answer :

A distributed object model for Java program to Java program, in which the methods of remote objects written in the Java programming language can be invoked from other Java virtual machines1, possibly on different hosts.


Question 24 :

What is Java Runtime Environment (JRE) ?

Answer :

A subset of the Java Development Kit (JDK) for end-users and developers who want to redistribute the runtime environment alone. The Java runtime environment consists of the Java virtual machine1, the Java core classes, and supporting files.


Question 25 :

What is Java virtual machine ?

Answer :

A software "execution engine" that safely and compatibly executes the byte codes in Java class files on a microprocessor (whether in a computer or in another electronic device).