How to install Java JDK and JRE? | What is java?

What is Java and How to install Java JDK and JRE?

Java is a general purpose, high-level programming language developed by Sun Microsystems. Java is a computer-programming language that is concurrent, class-based, object-oriented, and specifically designed to have as few implementation dependencies as possible. It is intended to let application developers "write once, run anywhere" (WORA), meaning that compiled Java code can run on all platforms that support Java without the need for recompilation. Java applications are typically compiled to bytecode that can run on any Java virtual machine (JVM) regardless of computer architecture. As of 2016, Java is one of the most popular programming languages in use, particularly for client-server web applications, with a reported 9 million developers. Java was originally developed by James Gosling at Sun Microsystems (which has since been acquired by Oracle Corporation) and released in 1995 as a core component of Sun Microsystems Java platform.

To install Java JDK and JRE

Go to this link and install the appropriate version according to your choice.
After that you are required to set the path variable.

Setting the PATH Environment Variable

To set the PATH variable on Microsoft Windows:

1. Select Control Panel and then System.
2. Click Advanced and then Environment Variables.
3. Add the location of the bin folder of the JDK installation ("C:\Program Files\Java\jdk-9\bin") to the PATH variable in System Variables.

If you do not set the PATH variable, then you must specify the full path to the executable file every time that you run it. For example:

C:\> "C:Program Files\Java\jdk-9\bin\javac" ClassFile.java