The Java platform refers to the combination of the Java programming language, the Java Virtual Machine (JVM), and a set of libraries and APIs (Application Programming Interfaces) that enable developers to create and run Java applications. The platform is designed to be cross-platform, meaning that Java applications can run on various operating systems without modification, as long as the JVM is available for that platform.

Here are the key components of the Java platform:

1. Java Programming Language: Java is a high-level, object-oriented programming language developed by Sun Microsystems (now owned by Oracle Corporation). It is known for its simplicity, portability, and write-once-run-anywhere (WORA) capability.

2. Java Virtual Machine (JVM): The JVM is an essential part of the Java platform. It is a virtual machine that executes Java bytecode, which is the compiled output of Java source code. The JVM abstracts the underlying hardware and operating system, providing a consistent environment for Java applications to run on different platforms.

3. Java API and Libraries: Java comes with an extensive standard library (Java Class Library) that provides a wide range of functions and tools for common tasks, such as networking, file I/O, database access, GUI development, and more. Developers can also use third-party libraries and frameworks to extend the capabilities of their Java applications.

4. Java Development Kit (JDK): The JDK is a software package that includes all the tools required for Java development, such as the compiler, JVM, and various utilities. It is necessary to write, compile, and run Java applications.

5. Java Runtime Environment (JRE): The JRE is a subset of the JDK that only includes the JVM and essential libraries required to run Java applications. End-users need the JRE installed on their machines to execute Java programs.