Java Standard Edition (Java SE) is a widely used programming platform that provides the core functionality for developing and running Java applications. It includes essential libraries, tools, and a runtime environment, allowing developers to create desktop applications, server-side applications, and more. Java SE is part of the larger Java Platform, which also includes Java Enterprise Edition (Java EE) for enterprise applications and Java Micro Edition (Java ME) for mobile devices. The platform is known for its portability, as Java applications can run on any device that has a compatible Java Virtual Machine (JVM).