See the Javadocs in <EPM_ORACLE_HOME>/common/docs/ReportingAnalysis/SDK/javadoc.
When artifacts are stored in EPM Workspace, they are associated with a metatype or artifact type that enables your program to filter search operations based on artifact type, and by keyword searches or by name. This class provides static methods that enable you to extract predefined ObjectType class instance variables that represent all built-in types found in EPM Workspace.