When talking about Java, people use Java, JVM, JDK, SDK, and Java platform as synonyms. The legal definition treats Java as Sun's trademark for a set of technologies, but we typically do not think about Java as a trademark. Most often, when somebody says Java, they mean a programming language that is used by humans to express sets of instructions (programs) that can be executed by a computer (not directly, but after the program is compiled/transformed into code that a computer understands). The human-readable Java program is called source code, and the computer-readable program (after all transformations) is called binary code, because it is expressed only using 1 and 0.
You can find the complete Java Language Specification (description) ...
