JavaScript and Java are often confused due to their similar names. But that's where most of the similarity ends. JavaScript does resemble Java in a few general ways, but it's a lot looser in terms of data typing, and it's an interpreted language, which means that JavaScript code is compiled at runtime by the client. A Java developer using the Java Developer Kit or a built-in compiler in a Java editor compiles Java, and the compiled code is sent to the client machine to be executed by the Java Virtual Machine (JVM) on the client.