Let's start with the JDK:

Java Development Kit (abbreviated as JDK) is a free Java application development kit provided by Oracle Corporation (formerly Sun Microsystems), including a Java compiler (javac), standard Java class libraries, examples, documentation, various utilities, and a Java executable ( JRE) .

JRE:

Java Runtime Environment (abbr. JRE; Russian. Runtime for Java ) is the minimal implementation of a virtual machine necessary for running Java applications without a compiler and other development tools. It consists of a virtual machine - Java Virtual Machine - and a library of Java classes.

So how to understand all the same, JRE is a Java runtime system or is it a Java runtime environment?

One is written in the JDK, the other in the JRE. All material is taken from Wikipedia.

    2 answers 2

    The execution system and the runtime are one and the same.

      In my understanding, JRE is needed for a developer to run projects in runtime mode. So that when editing you do not need to rebuild the project 10 times. For example, deployment was enough. I may be wrong of course, but I understand it somehow.

      Well, the JDK for the user of the product itself, that would run the java application.

      • I know what a JDK is, just about JRE I dig deeper to understand more specifically. - Petrovchenko Ivan
      • @PetrovchenkoIvan since it contains JVM, I can say that thanks to JRE you can run web applications on java, deploy them without compiling the project. I honestly did not really delve into it. At least this is what I know about JRE. - Alexey Zemtsov
      • What is warm? - Petrovchenko Ivan
      • Just the opposite. JDK - for development. So after all it is written - Developer Kit - a developer kit. And JRE is a runtime environment that does not require a compiler, and so on. It is for launching applications (for example, executable .jar-files. Well, a set of launch libraries is needed so that the JVM knows what is where - Oleksiy Morenets