An EAR file is an application archive used by Java EE (Enterprise Edition), a platform used for programming server-side software such as web applications. It contains .JAR and .WAR files, which together comprise a Java EE application package. EAR files are used for running the application on a Java EE-enabled server, such as GlassFish Server or Geronimo.
EAR files are similar to .JAR files, but they are packaged for Java EE instead of the Java SE (Standard Edition). Both JAR and EAR files use .ZIP compression, which means you can use Zip decompression programs, such as 7-Zip, to unpack the contents of the files.
NOTE: Java EE application are developed using the Java EE SDK, which can be downloaded from Oracle's website. Java EE adds additional features to Java SE for server programming.