What is the difference between JRE and regular Java?

Question

Java

What is the difference between JRE and regular Java which we download from java.com main page? I searched all over the Internet, everywhere they tell the difference between JRE, JDK, etc., but what is regular Java?

Answer 1

The "Java" you download from the main page is the JRE.

Answer 2

Java is the language itself (a set of specifications and guidelines).
JRE (java runtime enviroment) is a runtime environment for the java language, i.e. jvm and a set of libraries. Those. what the prebuilt java code
JDK (java developer kit) does is a set of coding tools and the included JRE. Here, in addition to the JRE, there are utilities for development (compiler, etc.)
JVM (java virtual machine) virtual machine (hardware) that executes the byte code of the language
I will add food for thought about the phrase that java is specifications and recommendations. For example Java in android is not the same as in java se for PC\Mac\Linux. Not the same as java ME, not the same as Java embendet. Etc. . All of the above are based on Java specifications and implemented in one way or another, but the lion's share of the code is compatible and leads to the expected results. Those. relatively speaking, java is concrete, but what is made of this concrete, and this can be a cellar \ barn \ house \ skyscraper \ shopping center is already a specific implementation of specifications and recommendations or discrepancies with them. By the way, there are many implementations of java vm. All JSR specs can be found here and use them to implement any aspect of java or the jvm itself.

Answer 3

JRE - Java Runtime Environment - Java runtime environment (this is the "normal", as already said)
JDK - Java Development Kit - a toolkit for a Java program developer (compiler, libraries, some other crap)