JDK - Java Development Kit
JDK contains the Java development tool kit with the Java Run time Environment. Basically this is required for Java development. Testing & deployment will also be supported as this contains the JRE and the other required tools along.http://www.oracle.com/technetwork/java/javase/downloads/jdk10-downloads-4416644.html
JRE - Java Run time Environment
JRE is the run time which helps to run a java program. If you want to run Java program but not to develop, you can use JRE straightly.http://www.oracle.com/technetwork/java/javase/downloads/jre10-downloads-4417026.html
What should I install ?
JDK for developing Java Applications. JRE for running Java Applications, but not for developing them....
