• Comp00.java | comp.tar.gz
  [ application class using package compa package compb ]
• Comp01.java
  [ application class using package compa package compb ]

compa /
[ package compa has interface ICompA and implementation class CompA ]

• ICompA.java
  [ interface in package compa ]
• CompA.java
  [ implementation class in package compa ]

compb /
[ package compb has interface ICompB and implementation class CompB ]

• ICompB.java
  [ interface in package compb ]
• CompB.java
  [ implementation class in package compb ]

compab /
[ packages compa compb are collected into compab.jar ]

• compab/compab.jar
  [ jar file with two packages compa and compb ]

• classpath.txt
  [ unix or windows jar extension and access ]