war - web archive. It is used to deploy web applications according to the servlet standard. It is a jar file containing a special directory called WEB-INF and several files and directories inside it (web.xml, lib, classes) as well as all the HTML, JSP, images, CSS, JavaScript and other resources of the web application
ear - enterprise archive. It is used to deploy enterprise application containing EJBs, web applications, and 3rd party libraries. It is also a jar file, it has a special directory called APP-INF that contains the application.xml file, and it contains jar and war files.