A Java Developer is responsible for the design, development, and management of Java-based applications. Because Java is used so widely, particularly by large organizations, the daily roles vary widely, but can include owning a particular application or working on several at one time.

Java is an influential language, as many languages have descended from it, including:

• PHP
• Python
• Scala
• JavaScript

Interestingly, PHP, a Java descendant, is used in over 82% of websites whose server-side programming is known.

Applications of Java Programming language: 

• Desktop GUI Applications development.
• Android and Mobile application development.
• Applications of Java are in embedded technologies like SIM cards, disc players, TVs, etc.
• Java EE (Enterprise Edition) provides an API and runtime environment for running large enterprise software.
• Network Applications and Web services like Internet connection, Web App Development.