> [!tldr] Modeling supports queries. Diagramming supports communication. Know which you're doing.
In practice I hear people talk about [[Disambiguating Systems and Architectures|systems and architecture]] **modeling** and **diagramming** as though they are the same thing and interchangeable. They are not the same thing, and the difference is more than [[Pedantic|pedantry]].
Models may be built with diagrams. Diagrams may be built with models. **But they serve fundamentally different groups** and [[What are You Optimizing For|need to be optimized for different purposes]], which *substantially* changes how they are done.
![[Modeling is different than diagramming. 2026-09-17 08.37.27.excalidraw.svg]]
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> [!warning] I've never seen a individual product that adequately serves both purposes.
| | Modeling | Diagramming |
| ---------------------------------- | --------------------------------------------------------------------------------------------------- | ------------------------------------------------------------------------------------------------ |
| Purpose | **Analysis**<br>- *Determining* the answers to questions | **Communication**<br>- *Presenting* the answers to questions |
| Audience | **Modelers** | **Non-modelers** |
| Audience expectaiton | Users understand the syntax <br>Users trade simplicity for technical accuracy and comprehensiveness | Users do not know syntax <br>Users trade technical accuracy and comprehensiveness for simplicity |
| Tooling | Database-oriented<br>Examples: Cameo, [[Archi]], Genesys | Graphic-oriented<br>Examples: [[DrawIO]], [[Excalidraw]] |
| Optimized for | Analysis - queries, technical accuracy, comprehensiveness | Ease of comprehension, clarity, saying what needs said rather than everything that could be said |
| Syntax & ontological "correctness" | Matters | Does not matter |
| Level of abstraction | High fidelity | High level |
...turns out I already have a note about how [[Modeling is for Simulations and Computers, Diagramming is for Communication and Humans]].
And I made this graphic, which I haven't used enough:
![[Systems Modeling Exists on a Spectrum 2026-04-18 14.52.36.excalidraw.svg]]
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## Tooling
You *can* use modeling tools to generate diagrams.
You *can* use diagramming tools to approximate models.
It's better to use the right tool for the right job. Or - at least - make your model outputs much more user-friendly if they're going out to broad audiences. Follow [[Diagram Best Practices]].
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# More
## Source
- self