Types of UML Diagrams

Get familiar with the types of UML diagrams.

We'll cover the following

UML diagrams can be classified into two categories:

  • Structural UML diagrams

  • Behavioral UML diagrams

The following illustration represents the subcategories of structural and behavioral UML diagrams:

Timing Diagram
Interaction Overview Diagram
Communication Diagram
Sequence Diagram
State Machine Diagram
Activity Diagram
Use Case Diagram
Deployment Diagram
Component Diagram
Composite Structure Diagram
Object Diagram
Class Diagram
Package Diagram
Interaction Diagrams
Implementation Diagrams
Behavioral Diagrams
Structural Diagrams
UML Diagrams
Types of UML diagrams

Structural UML diagrams#

Structural diagrams represent the static structure of the system. They never depict the system’s dynamic behavior. The most commonly used structural diagram in software development is the class diagram.

Behavioral UML diagrams #

Behavioral diagrams represent the dynamic behavior of elements in the system. All systems experience dynamic occurrences. In object-oriented programming, we use behavioral diagrams to illustrate the dynamic behavioral semantics of a problem or its implementation. The most commonly used behavioral diagrams are use case diagrams, activity diagrams, and sequence diagrams.

UML diagrams used in the OOD interview#

In a typical OOD interview process, the following are the most widely asked UML diagrams:

  • Use case diagram

  • Class diagram

  • Sequence diagram

  • Activity diagram

Note: The class diagram belongs to the structural diagrams and the use case, sequence, and activity diagrams belong to the behavioral diagrams category of the UML.

The next few lessons will cover all the four UML diagrams above, in detail.

Introduction to the Unified Modeling Language

Use Case Diagram