What do you mean by
What is UML? You mean you dont know what UML is? If so, UML means Unitifed Modelling Language.
You can have more info at:
http://www.uml.org/ The exam objectives described explicitly what you need to know:
2.1 Recognize the UML representation of classes, (including attributes and operations, abstract classes, and interfaces), the UML representation of inheritance (both implementation and interface), and the UML representation of class member visibility modifiers (-/private and +/public).
2.2 Recognize the UML representation of class associations, compositions, association multiplicity indicators, and association navigation indicators.
Refers to the UML specification for the required topics.
Nick
SCJP 1.2, OCP 9i DBA, SCWCD 1.3, SCJP 1.4 (SAI), SCJD 1.4, SCWCD 1.4 (Beta), ICED (IBM 287, IBM 484, IBM 486), SCMAD 1.0 (Beta), SCBCD 1.3, ICSD (IBM 288), ICDBA (IBM 700, IBM 701), SCDJWS, ICSD (IBM 348), OCP 10g DBA (Beta), SCJP 5.0 (Beta), SCJA 1.0 (Beta), MCP(70-270), SCBCD 5.0 (Beta), SCJP 6.0, SCEA for JEE5 (in progress)