Ideal for explaining relationships, not appearances.

Code

erDiagram
    PERSON ||--o{ SPEECH : delivers
    SPEECH ||--o{ EVALUATION : receives
    EVALUATION }o--|| JUDGE : given_by

    PERSON {
        string name
        string role
    }

    SPEECH {
        string title
        int duration
    }

    JUDGE {
        string name
        int experienceLevel
    }

Rendered Diagram

erDiagram
    PERSON ||--o{ SPEECH : delivers
    SPEECH ||--o{ EVALUATION : receives
    EVALUATION }o--|| JUDGE : given_by

    PERSON {
        string name
        string role
    }

    SPEECH {
        string title
        int duration
    }

    JUDGE {
        string name
        int experienceLevel
    }

---

Significance

Why this is gold: ERDs are pure structure—no visual imagination required.