The Java Runtime Environment (JRE) is a software layer that runs on top of a computers operating system software and provides the class libraries and other resources that a specific Java program needs to run. It is one of the three interrelated components required for developing and running Java programs, the other two being the Java Development Kit (JDK) and the Java Virtual Machine (JVM). The JRE combines Java code created using the JDK with the necessary libraries required to run it on a JVM and then creates an instance of the JVM that executes the resulting program. The JRE is important because it facilitates platform independence for Java applications, allowing them to run on any operating system without further modifications. The JRE is made up of a Java virtual machine (JVM), Java class libraries, and the Java class loader. The JVM is an abstract machine that provides a runtime environment in which Java bytecode can be executed. The Java class libraries contain collections of prewritten code that can be called when needed. The class loader connects class libraries with the JVM and loads them. The JRE also includes deployment technologies such as Java Web Start and Java Plugin that simplify the activation of applications and provide advanced support for future Java updates.