class

• 
• Represents complex object types. In OO design parlance, such objects are identified with a separate identifier, in contrast to value types whichiare identified by their value. If the name is in italics it indicates the clas is abstract, i.e. no instances of this class can be made directly, only indirectly through concrete(=non-abstract) sub-classes.

datatype

• symbol:
  
• Represents a value type. Examples are the primitive types such as integer, real, string, but also higher dimensional points, and certain structured value types.

enumeration

attribute

inheritance

collection/composition

reference

subsets

stereotype

package