Unit 1

• Use Case Diagram → https://www.geeksforgeeks.org/use-case-diagram/?ref=lbp
• Class Diagram → https://www.geeksforgeeks.org/unified-modeling-language-uml-class-diagrams/?ref=lbp

Unit 2

• Interaction Diagram → https://www.visual-paradigm.com/guide/uml-unified-modeling-language/what-is-interaction-overview-diagram/
• Sequence Diagram → https://www.visual-paradigm.com/guide/uml-unified-modeling-language/what-is-sequence-diagram/ for exam prep → https://www.geeksforgeeks.org/unified-modeling-language-uml-sequence-diagrams/
• Collaboration Diagram → https://www.geeksforgeeks.org/collaboration-diagrams-unified-modeling-languageuml/

Unit 3

• State Chart Diagram → https://www.geeksforgeeks.org/unified-modeling-language-uml-state-diagrams/ further reading (a comparison with Activity) → https://www.visual-paradigm.com/guide/uml-unified-modeling-language/about-state-diagrams/
• Activity Diagram → https://www.visual-paradigm.com/guide/uml-unified-modeling-language/what-is-activity-diagram/

Softwares

• Online Draw → https://www.smartdraw.com/Ins
• Installable Standalone → ArgoUML (search for this name), StarUML