Seven Popular UML Diagrams

Let's first have a defintion for UML(from Wikipedia) = "A general-purpose, developmental, modeling language that is intended to provide a standard way to visualize the design of a system”. UML is a modeling language used by software developers to develop diagrams and provide users (programmers) with ready-to-use, expressive modeling examples.

Next we will have a look a the most commonly used Diagram types:

1. The Component Diagram

• Shows components
• Shows implemented and required interfaces
• Components can be nested

2. The Class Diagram

• Shows classes
• Shows methods and fields
• Shows associations, generalizations, and cardinality

3. The Sequence Diagram

• Shows call sequence
• Shows calling class, called method, and return data type
• Can depict loops

4. The State Diagram

• Shows states or activities
• Shows allowed transitions
• Can be nested
• Can depict internal activities

5. The Activity Diagram

• Shows process or workflow
• Can be nested
• Can show concurrent actions
• Can have swim lanes

6. The Layer Diagram

• Non-standard, invented by MS
• Shows areas of concern
• Shows references between areas
• Can be validated

7. The Use Case Diagram

• Shows actors
• Shows use cases
• Binds actors to use cases
• Can depict generalizations

14.07.2021