# 28 Visual Diagram Types in diagram-design: Complete Guide with Use Cases > Explore 28 visual diagram types in diagram-design with this complete guide. Discover use cases and learn how to leverage this powerful tool for clear communication and problem solving. - Repository: [Cathryn Lavery/diagram-design](https://github.com/cathrynlavery/diagram-design) - Tags: deep-dive - Published: 2026-08-18 --- **Diagram-design ships a fixed taxonomy of 28 visual diagram types**, each with dedicated reference documentation under `skills/diagram-design/references/` and unified rendering through a single core engine. The diagram-design repository by Cathryn Lavery organizes visual communication into a strict, extensible system. Whether you're importing Mermaid files, converting Draw.io diagrams, or exporting to HTML, understanding these 28 diagram types ensures you select the right layout for your data. This guide covers every type, its intended use case, and how to invoke it via the CLI. --- ## Complete List of 28 Diagram Types in diagram-design The source code defines **28 distinct diagram types** across six functional categories. Each type lives in its own markdown specification file. ### Classic Charting Types These handle quantitative data visualization: - **Bar** ([`type-bar.md`](https://github.com/cathrynlavery/diagram-design/blob/main/type-bar.md)): Categorical comparisons, distributions, and rankings - **Line** ([`type-line.md`](https://github.com/cathrynlavery/diagram-design/blob/main/type-line.md)): Trends over time, continuous data progression - **Scatter** ([`type-scatter.md`](https://github.com/cathrynlavery/diagram-design/blob/main/type-scatter.md)): Correlation analysis, outlier detection - **Radar** ([`type-radar.md`](https://github.com/cathrynlavery/diagram-design/blob/main/type-radar.md)): Multi-variable performance profiles, skill assessments ### Hierarchical Structure Types For parent-child relationships and nested information: - **Tree** ([`type-tree.md`](https://github.com/cathrynlavery/diagram-design/blob/main/type-tree.md)): File systems, decision trees, taxonomies - **Org-Chart** ([`type-org-chart.md`](https://github.com/cathrynlavery/diagram-design/blob/main/type-org-chart.md)): Company hierarchies, reporting structures - **Architecture** ([`type-architecture.md`](https://github.com/cathrynlavery/diagram-design/blob/main/type-architecture.md)): System components, deployment topologies - **Nested** ([`type-nested.md`](https://github.com/cathrynlavery/diagram-design/blob/main/type-nested.md)): Containers-within-containers, Russian doll layouts ### Process and Flow Types For temporal sequences and operational flows: - **Flowchart** ([`type-flowchart.md`](https://github.com/cathrynlavery/diagram-design/blob/main/type-flowchart.md)): Algorithm logic, business processes, decision paths - **Process** ([`type-process.md`](https://github.com/cathrynlavery/diagram-design/blob/main/type-process.md)): Step-by-step workflows with clear start/end points - **High-Level** ([`type-high-level.md`](https://github.com/cathrynlavery/diagram-design/blob/main/type-high-level.md)): Executive summaries, simplified system overviews - **Sequence** ([`type-sequence.md`](https://github.com/cathrynlavery/diagram-design/blob/main/type-sequence.md)): Object interactions, API call flows, system dynamics - **Timeline** ([`type-timeline.md`](https://github.com/cathrynlavery/diagram-design/blob/main/type-timeline.md)): Historical events, project milestones, roadmaps - **Swimlane** ([`type-swimlane.md`](https://github.com/cathrynlavery/diagram-design/blob/main/type-swimlane.md)): Cross-functional processes, role-based activities - **Gantt** ([`type-gantt.md`](https://github.com/cathrynlavery/diagram-design/blob/main/type-gantt.md)): Project scheduling, dependency tracking, resource allocation ### State-Based Visualization Types For condition transitions and security modeling: - **State** ([`type-state.md`](https://github.com/cathrynlavery/diagram-design/blob/main/type-state.md)): Finite state machines, UI component lifecycles - **IT State** ([`type-it-state.md`](https://github.com/cathrynlavery/diagram-design/blob/main/type-it-state.md)): Infrastructure states, service health transitions - **Data Flow** ([`type-data-flow.md`](https://github.com/cathrynlavery/diagram-design/blob/main/type-data-flow.md)): Information movement through systems, GDPR/privacy mapping - **DP Security Matrix** ([`type-dp-security-matrix.md`](https://github.com/cathrynlavery/diagram-design/blob/main/type-dp-security-matrix.md)): Data protection risk assessment, compliance grids - **DP Integration** ([`type-dp-integration.md`](https://github.com/cathrynlavery/diagram-design/blob/main/type-dp-integration.md)): Data protection system interoperability ### Specialized Layout Types For conceptual and strategic frameworks: - **Venn** ([`type-venn.md`](https://github.com/cathrynlavery/diagram-design/blob/main/type-venn.md)): Set relationships, overlapping audience segments - **Quadrant** ([`type-quadrant.md`](https://github.com/cathrynlavery/diagram-design/blob/main/type-quadrant.md)): 2x2 matrices, competitive positioning, prioritization grids - **Pyramid** ([`type-pyramid.md`](https://github.com/cathrynlavery/diagram-design/blob/main/type-pyramid.md)): Hierarchical value, Maslow-style needs, food chains - **Medallion** ([`type-medallion.md`](https://github.com/cathrynlavery/diagram-design/blob/main/type-medallion.md)): Centralized hub-and-spoke, core-periphery relationships - **Loop** ([`type-loop.md`](https://github.com/cathrynlavery/diagram-design/blob/main/type-loop.md)): Cyclical processes, feedback loops, continuous improvement - **Layers** ([`type-layers.md`](https://github.com/cathrynlavery/diagram-design/blob/main/type-layers.md)): OSI stack-style abstractions, cake-layer architectures - **ER** ([`type-er.md`](https://github.com/cathrynlavery/diagram-design/blob/main/type-er.md)): Entity-relationship modeling, database schema design --- ## How to Specify Diagram Types in diagram-design The CLI exposes diagram type selection through the `--type` flag. Override automatic detection when your source format is ambiguous. ### Import with Explicit Type ```bash diagram-design import-mermaid my-diagram.mmd --type gantt ``` ```bash diagram-design import-drawio my-diagram.drawio --type architecture ``` ### Export with Default Type Detection ```bash diagram-design export-diagram --output diagram.html ``` When omitted, the engine infers type from source content structure. The reference files in `skills/diagram-design/references/*.md` define the inference rules. --- ## Key Implementation Files | File Path | Purpose | |-----------|---------| | `skills/diagram-design/references/type-*.md` | Authoritative specifications for all 28 diagram types | | [`commands/import-mermaid.md`](https://github.com/cathrynlavery/diagram-design/blob/main/commands/import-mermaid.md) | Mermaid import CLI with `--type` option | | [`commands/import-drawio.md`](https://github.com/cathrynlavery/diagram-design/blob/main/commands/import-drawio.md) | Draw.io import CLI with `--type` option | | [`commands/export-diagram.md`](https://github.com/cathrynlavery/diagram-design/blob/main/commands/export-diagram.md) | Export to HTML/PNG documentation | | `assets/template-*.html` | Rendering templates (light, dark, full variants) | | `scripts/*.py` | Validation scripts enforcing type-specific constraints | The Python validation scripts apply specialized rules: for example, **DP Security Matrix** has strict edge constraints checked at build time. --- ## When to Use Each Diagram Type Category Choose based on your communication goal: - **Quantitative comparison** → Bar, Line, Scatter, Radar - **Organizational clarity** → Tree, Org-Chart, Nested - **Process documentation** → Flowchart, Sequence, Swimlane, Gantt - **System modeling** → Architecture, Layers, Data Flow, ER - **Compliance and security** → DP Security Matrix, DP Integration, IT State - **Strategic frameworks** → Quadrant, Pyramid, Venn, Medallion The diagram-design engine normalizes all inputs to these 28 canonical types, ensuring consistent output regardless of source format. --- ## Summary - Diagram-design defines **28 fixed diagram types** in `skills/diagram-design/references/` - Types span charting, hierarchy, process, state, security, and specialized layouts - Use `--type` flag to override automatic detection: `import-mermaid`, `import-drawio` - Each type has dedicated validation rules enforced by Python scripts - HTML templates in `assets/` render final output in multiple themes --- ## Frequently Asked Questions ### How does diagram-design handle automatic type detection? The engine analyzes source structure—Mermaid grammar tokens, Draw.io XML shapes, or JSON schema—to infer type. When ambiguous, it defaults to generic Flowchart or requires explicit `--type` specification per [`commands/import-mermaid.md`](https://github.com/cathrynlavery/diagram-design/blob/main/commands/import-mermaid.md). ### Can I create custom diagram types beyond the 28? No. The taxonomy is fixed. The repository enforces this through validation scripts that reject unknown types. Extending requires modifying `scripts/*.py` and adding a new `type-*.md` reference file. ### What's the difference between State and IT State diagram types? **State** ([`type-state.md`](https://github.com/cathrynlavery/diagram-design/blob/main/type-state.md)) models general finite state machines for software components. **IT State** ([`type-it-state.md`](https://github.com/cathrynlavery/diagram-design/blob/main/type-it-state.md)) specializes in infrastructure monitoring, capturing service health transitions (up, degraded, down) with operational metadata. ### Which diagram type should I use for GDPR compliance documentation? Use **DP Security Matrix** for risk assessment grids and **DP Integration** for mapping how data protection systems connect. Both enforce data-flow-specific validation rules absent in generic diagram types.