What is the different between JDK and SDK?

I am using Win XP and Internet Explorer, how to install the latest Java Virtual Machine?

Instructions to install of JVM

http://java.sun.com/j2se/1.4.2/install-windows.html

Source from sun web site for JDK & SDK:
Well I think you need JDK from J2SE and some IDE for development Java
programs (JBuilder, Forte, NetBeans)

JDK = Java Development Kit - if you want to develop or just compile Java
programs (*.java -> *.class -> *.jar)
JRE = Java Runtime Environment - if you want to execute a Java program

Just my simple descriptions:
J2SE = Java 2 Standard Edition - (JDK+JRE) - for common purposes for example
on PCs
J2EE = Java 2 Enterprise Edition - AFAIK framework and methodology to
produce applications in 3-layer technology (robust applications)
J2ME = Java 2 Micro Edition - (JDK+JRE) - for small devices (cellular
phones, palmtops etc.)

SDK = Software Development Kit.
It follows some fundamental infos from Sun's website:
--------------------------
J2SE
--------------------------
 The premier solution for rapidly developing and deploying mission-critical,
enterprise applications, J2SETM provides the essential compiler, tools,
runtimes, and APIs for writing, deploying, and running applets and
applications in the Java programming language.

--------------------------
J2EE
--------------------------
 J2EETM technology and its component based model simplifies enterprise
development and deployment. The J2EE platform manages the infrastructure and
supports the Web services to enable development of secure, robust and
interoperable business applications. The J2EE platform is the foundation
technology of the Sun ONE platform and Sun's Web services strategy.

--------------------------
J2ME
--------------------------
A highly optimized Java runtime environment, J2METM technology specifically
addresses the vast consumer space, which covers the range of extremely tiny
commodities such as smart cards or a pager all the way up to the set-top
box, an appliance almost as powerful as a computer.

So, it means that to develop a Java program, then I should have JDK + JRE + IDE?

Just few days before, I get something from internet like "JCreator LE". This JCreator LE = IDE? If JCreator is a kind of IDE, then I should install JDK and JRE first, rite?

But yesterday I went to Sun web site, I have downloaded Java 2 SDK SE v1.4.1_02 and is already installed to my pc. In this case, can I just use SDK + JRE + IDE to run the Java application?

How can we know whether the JVM is already installed into window?


Chuah

SDK is what you need to write and compile your own code.

JDK is what you need to run already compiled code.

IDE is a tool to help write code.

To check which version you have installed:
Start > run > type 'cmd' (enter) in new window > type 'java -version' (enter)

Is it something like, when we install SDK, JDK have already included in in the SDK? And if I am not mistaken, there are something like "public" JDK and "private" JDK. Do you have any idea what are diffrences between those two stuff?

Yes... JDK, in a sense, is included with the SDK. There is not a public and private JDK... I have no idea what purpose that would serve anyhow. Similiar to Flash, the JDK is java's 'plug-in" for users to view applets or run java applications.

Sorry, I have mentioned the wrong questions the other days. Anyhow, it is as quoted below:

 

Sorry again, that day I tried to ask what is public "J2RE" and private "J2RE" but not public or private "JDK". I ask the wrong question,

Do you have any idea what is that actually?

Ya, Gator, have you ever create a web page by using only applet with minimal HTML coding? I mean all the images, fonts, buttons and so on are drawn in applet, but not using any HTML code such as <IMAGE>, and so forth.

I'll be honest, I never heard of a public/private J2RE, but I looked it up out of curiousity and found this:

"Private vs. public J2RE - Installing the Java 2 SDK installs a private Java 2 Runtime Environment and optionally a public copy. The private J2RE is required to run the tools included with the Java 2 SDK. It has no registry settings and is contained entirely in a jre directory (typically at C:\Program Files\j2sdk1.4.2\jre) whose location is known only to the SDK. On the other hand, the public J2RE can be used by other Java applications, is contained outside the SDK (typically at C:\Program Files\Java\j2re1.4.2), is registered with the Windows registry (at HKEY_LOCAL_MACHINE\SOFTWARE\JavaSoft), can be removed using Add/Remove Programs, might or might not be registered with browsers, and might or might not have java.exe copied to the Windows system directory (making it the default system Java platform or not)."

If I understand this correctly, when you install the SDK you get a private J2RE. Theres an option to install the public version instead in the install. The difference is one works with only the SDK (private), while the other is for use with any Java apps located on your system.


I've created tons of applets with minimal HTML that include GUI widgets.

I agree with you too regarding to what are those private and public J2RE. I went to Sun Java site, I have read the same explanation too but still confuse about it, but it makes sense after what you have replied me.

 

So, it means that applet with minimal html is possible. Would you mind to share me one or two pages coding of your applet (simple and short coding is suffice) so that I will have much clearer idea on how you do it.