Advance Java is next level concept of JAVA Programming. It is used for developing the web based application and enterprise application. So Advanced Java is nothing but specialization in domains such as web, networking, database handling.
Its also a programming language based on GUI application.
There are a lot of Advance Java frameworks like Spring, JSF, Struts etc. which enable you to develop a secure transaction based web apps for the domains like E-Commerce, Banking, Legal, Financial, Healthcare, Inventory etc.
To work and understand the hot technologies like Hadoop and Cloud services, you should be prepared with core and advanced Java concepts.