Explain what a fat JAR file is and its features.

Fat JAR (or Uber JAR) is a JAR file that contains not only the compiled code of your application but also all its dependencies (libraries and resources). This allows you to run the application from a single file without the need to manage dependencies separately.

Features of fat JAR:

• Simplifies deployment and execution of the application.
• Can significantly increase the size of the final file.
• Requires careful assembly to avoid conflicts between dependencies.

An example of creating a fat JAR using the Maven plugin maven-shade-plugin allows you to package all dependencies into one JAR.