UML class diagram - Metadata information model

"Metadata is "data about data". The term is ambiguous, as it is used for two fundamentally different concepts (types). Structural metadata is about the design and specification of data structures and is more properly called "data about the containers of data"; descriptive metadata, on the other hand, is about individual instances of application data, the data content.
Metadata are traditionally found in the card catalogs of libraries. As information has become increasingly digital, metadata are also used to describe digital data using metadata standards specific to a particular discipline. By describing the contents and context of data files, the quality of the original data/ files is greatly increased. For example, a webpage may include metadata specifying what language it is written in, what tools were used to create it, and where to go for more on the subject, allowing browsers to automatically improve the experience of users." [Metadata. Wikipedia]
The UML class diagram example "Metadata information model" was created using the ConceptDraw PRO diagramming and vector drawing software extended with the Rapid UML solution from the Software Development area of ConceptDraw Solution Park.

"In software engineering, a class diagram in the Unified Modeling Language (UML) is a type of static structure diagram that describes the structure of a system by showing the system's classes, their attributes, operations (or methods), and the relationships among objects. ...
The class diagram is the main building block of object oriented modelling. It is used both for general conceptual modelling of the systematics of the application, and for detailed modelling translating the models into programming code. Class diagrams can also be used for data modeling. The classes in a class diagram represent both the main objects, interactions in the application and the classes to be programmed." [Class diagram. Wikipedia]
The template "UML class diagram" for the ConceptDraw PRO diagramming and vector drawing software is included in the Rapid UML solution from the Software Development area of ConceptDraw Solution Park.
www.conceptdraw.com/ solution-park/ software-uml

The vector stencils library "UML class diagrams" contains 38 symbols for the ConceptDraw PRO diagramming and vector drawing software.
"... classes are represented with boxes which contain three parts:
(1) The top part contains the name of the class. It is printed in Bold, centered and the first letter capitalized.
(2) The middle part contains the attributes of the class. They are left aligned and the first letter is lower case.
(3) The bottom part gives the methods or operations the class can take or undertake. They are also left aligned and the first letter is lower case. ...
To indicate a classifier scope for a member, its name must be underlined. ...
An association can be named, and the ends of an association can be adorned with role names, ownership indicators, multiplicity, visibility, and other properties. ...
Aggregation ... is graphically represented as a hollow diamond shape on the containing class end of the tree with a single line that connects the contained class to the containing class.
... graphical representation of a composition relationship is a filled diamond shape on the containing class end of the tree of lines that connect contained class(es) to the containing class.
... graphical representation of a Generalization is a hollow triangle shape on the superclass end of the line (or tree of lines) that connects it to one or more subtypes.
... graphical representation of a Realization is a hollow triangle shape on the interface end of the dashed line (or tree of lines) that connects it to one or more implementers. A plain arrow head is used on the interface end of the dashed line that connects it to its users.
Multiplicity ... representation of an association is a line with an optional arrowhead indicating the role of the object(s) in the relationship, and an optional notation at each end indicating the multiplicity of instances of that entity (the number of objects that participate in the association).
Entity classes ... are drawn as circles with a short line attached to the bottom of the circle. Alternatively, they can be drawn as normal classes with the «entity» stereotype notation above the class name." [Class diagram. Wikipedia]
The example "Design elements - UML class diagrams" is included in the Rapid UML solution from the Software Development area of ConceptDraw Solution Park.

This example of UML class diagram models bank account system.
"A bank account is a financial account between a bank customer and a financial institution. A bank account can be a deposit account, a credit card, or any other type of account offered by a financial institution. The financial transactions which have occurred within a given period of time on a bank account are reported to the customer on a bank statement and the balance of the account at any point in time is the financial position of the customer with the institution. a fund that a customer has entrusted to a bank and from which the customer can make withdrawals." [Bank account. Wikipedia]
This bank account system UML class diagram example was created using the ConceptDraw PRO diagramming and vector drawing software extended with the ATM UML Diagrams solution from the Software Development area of ConceptDraw Solution Park.