Java Platform Enterprise Edition (J2EE) is a powerful platform for building enterprise-scale applications and web services. Coursera's J2EE skill catalogue teaches you to develop and deploy robust, scalable, and secure business applications using J2EE technologies. You'll learn about various J2EE components like Servlets, JavaServer Pages (JSP), Enterprise JavaBeans (EJB), Java Message Service (JMS), and more. Further, you'll delve into database connectivity using Java Database Connectivity (JDBC) and understand the role of Java Naming and Directory Interface (JNDI). By mastering J2EE, you'll be able to architect and implement multi-tier enterprise solutions, enhance your backend development skills, and excel in roles such as Java Developer, Software Engineer, and Application Developer.