Unified Modelling Language (UML) is a standard way to visualize the design of a system. 
Structural UML diagrams
Structural and Behavioural Diagrams are common known Types of UML Diagrams

Structural UML diagrams:
- Class diagram
- Package diagram
- Object diagram
- Component diagram
- Composite structure diagram
- Deployment diagram
- Behavioral UML diagrams

Behavioral UML diagrams:
- Activity diagram
- Sequence diagram
- Use case diagram
- State diagram
- Communication diagram
- Interaction overview diagram
- Timing diagram

The Unified Modeling Language (UML) is a general-purpose, developmental, 
modeling language in the field of software engineering that is intended 
to provide a standard way to visualize the design of a system. 

Types of UML Diagrams
-Structure diagrams
-Behavior diagrams
-Interaction diagrams

In software engineering UML is a fast way to understand a system and details of
what it is made of, how it behaves and what interactions exist