When I create Java code, I can create...
                
                
                
                A) a class to use used by an Application
                      Core Java used by every Java Appl
                B) a Decktop Java Appl (Tier III)
                      GUI based code 
                C) a Server Java Appl (Tier II - Linux Servers (JBoss))
                      Web Based Appl include Web Services
                      (Java Immersion - JIT)
                D) a IBM Mainframe Java Appl (Tier I)
                      Batch appl that process large amounts of data
                      (Mainframe Immersion - MFI) (our class)
                E) a Mobile device Java Appl (Tier IV)
                      (Angular, ReAct, etc - JavaScript)



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                is Core Java, the textbooks we have
                
                Core Java works on any Tier...
                  Part A (Comes w/ Java)
                
                we have a lot of pre-written Java classes
                we can use
                
                IBM adds a set of class to the Core Java
                that we can use ONLY on the IBM Mainframe
                  Part D (Comes w/ the Mainframe)
                  
                we can add other frameworks
                  third Party Frameworks
                  these we need to download and add ourselfs