JAR vs WAR file specification

Question

I noticed that WAR files are supposed to have classes/ and lib/ directories for containing their classfile root and dependencies, respectively.

Answer 1

WAR files (mainly WEB applications) are uncompressed, and all JAR files inside the lib folder will be in the classpath of your web application while running.

JAR files might also contain jar files, but will not be found and loaded by the default class loader.

There are special class loaders that do load jar files inside jar files, but not standard.