What is Java EE?
Java EE is a collection of specifications for developing and deploying enterprise applications.
In general, enterprise applications refer to software hosted on servers that provide the applications that support the enterprise.
The specifications (defined by Sun) describe services, application programming interfaces (APIs), and protocols.
The 13 core technologies that make up Java EE are:
- JDBC
- JNDI
- EJBs
- RMI
- JSP
- Java servlets
- XML
- JMS
- Java IDL
- JTS
- JTA
- JavaMail
- JAF
The Java EE product provider is typically an application-server, web-server, or database-system vendor who provides classes that implement the interfaces defined in the specifications. These vendors compete on implementations of the Java EE specifications.
When a company requires Java EE experience what are they really asking for is experience using the technologies that make up Java EE. Frequently, a company will only be using a subset of the Java EE technologies.
Java EE is actually a collection of technologies and APIs for the Java platform designed to support "Enterprise" Applications which can generally be classed as large-scale, distributed, transactional and highly-available applications designed to support mission-critical business requirements.
In terms of what an employee is looking for in specific techs, it is quite hard to say, because the playing field has kept changing over the last five years. It really is about the class of problems that are being solved more than anything else. Transactions and distribution are key.
J(2)EE, strictly speaking, is a set of APIs (as the current top answer has it) which enable a programmer to build distributed, transactional systems. The idea was to abstract away the complicated distributed, transactional bits (which would be implemented by a Container such as WebSphere or Weblogic), leaving the programmer to develop business logic free from worries about storage mechanisms and synchronization.
In reality, it was a cobbled-together, design-by-committee mish-mash, which was pushed pretty much for the benefit of vendors like IBM, Oracle and BEA so they could sell ridicously over-complicated, over-engineered, over-useless products. Which didn't have the most basic features (such as scheduling)!
J2EE was a marketing construct.