what is the use of JDK
JDK stands for Java Development Kit. It contains all necessary components used in Java programming such as class, method, swing, AWT, package, Java (interpreter), javac (compiler), appletviewer (applet application viewer), etc. To conclude, it contains every file required for developing applications, whether standalone or web-based.
The important reasons of using JDK:
JDK contains tools required to write Java programs, and JRE to execute them. It includes a compiler, Java application launcher, Appletviewer, etc. Compiler converts code written in Java into byte code. Java application launcher opens a JRE, loads the necessary class, and executes its main method.