JAR vs WAR

  1. Full Form:

    • JAR = Java ARchive
    • WAR = Web ARchive

  2. Purpose

    • JAR = Standalone Java apps or libraries
    • WAR = Web applications for servers

  3. Contents

    • JAR = .class files, resources, META-INF
    • WAR = Web files (HTML/JSP), WEB-INF, classes, libraries

  4. Deployment:

    • JAR = Run with java -jar
    • WAR = Deploy on web server (Tomcat, JBoss)

  5. Execution:

    • JAR = Executable (if Main-Class present)
    • WAR = Server-managed, not directly executable

  6. Scope:

    • JAR = Desktop/CLI apps, libraries
    • WAR = Web apps (servlets, JSP, REST APIs)

  7. Relationship:

    • WAR often contains JARs inside WEB-INF/lib.
    • JAR = Java app/library
    • WAR = Web app for server