What UML diagrams have you used?

In UML, the following diagrams are typically used depending on the tasks:

• Use Case diagrams — to describe the system's functionality from the user's perspective.
• Class diagrams — for modeling data structures and relationships between classes.
• Sequence diagrams — to display interactions between objects over time.
• Activity diagrams — to describe business processes and workflows.
• State diagrams — for modeling object states and transitions between them.

Depending on the project and requirements, one or more of these diagrams can be used for system analysis and design.