Java is a computer programming language that is concurrent, class-based, object-oriented, and specifically designed to have as few implementation dependencies as possible.
It is intended to let application developers "write once, run anywhere" (WORA), meaning that code that runs on one platform does not need to be recompiled to run on another. Java applications are typically compiled to bytecode (class file) that can run on any Java virtual machine (JVM) regardless of computer architecture.
Java is, as of 2012, one of the most popular programming languages in use, particularly for client-server web applications, with a reported 9 million developers.
Advanced Java modules are the most used tools in market today. They are widely used in industry and hence knowledge of these modules help candidates find good jobs in market. Advanced Java modules are very sought after skill as these skills are not easy to find among general candidates.