J2SE, or Java 2 Standard Edition, is a platform developed by Sun Microsystems for building and running Java applications. It provides a core set of libraries and tools that enable developers to create desktop applications, applets, and other software. J2SE introduced features like the Java Virtual Machine (JVM) and the Java Development Kit (JDK), which are essential for executing Java programs. Released in 1998, J2SE was a significant step in the evolution of the Java programming language. It laid the groundwork for later versions, such as Java SE, which continue to enhance functionality and performance. J2SE remains important for understanding the history and development of Java technologies.