Java is a programming language that produces software for multiple platforms. When a programmer writes a Java application, the compiled code (known as bytecode) runs on most operating systems (OS), including Windows, Linux, and Mac OS. Java derives much of its syntax from the C and C++ programming languages.

Java was developed in the mid-1990s by James A. Gosling, a former computer scientist with Sun Microsystems.

Java produces applets (browser-run programs), which facilitate graphical user interface (GUI) and object interaction by Internet users. Prior to Java applets, Web pages were typically static and non-interactive. Java applets have diminished in popularity with the release of competing products, such as Adobe Flash and Microsoft Silverlight.

Java applets run in a Web browser with Java Virtual Machine (JVM), which translates Java bytecode into native processor instructions and allows indirect OS or platform program execution. JVM provides the majority of components needed to run bytecode, which is usually smaller than executable programs written through other programming languages. Bytecode cannot run if a system lacks required JVM.