The Java Runtime Environment (JRE) is a software package that provides the necessary components to run Java applications. It includes the Java Virtual Machine (JVM), core libraries, and other files that support the execution of Java programs. The JRE allows developers and users to run Java applications without needing to install the full Java Development Kit (JDK). The JRE is essential for running applications written in the Java programming language. It ensures that Java programs can operate on various operating systems without modification, thanks to the platform-independent nature of Java. Users typically install the JRE to access Java-based applications, such as games or web applications.