Flowchart

flowchart LR A[Start] -- note for a line --> B((a path)) A --> C(The other path) B --> D{END} C --> D

Sequence

sequenceDiagram participant Alice participant Bob Alice->>John: Hello John, how are you? loop Healthcheck John->>John: Fight against hypochondria end Note right of John: Rational thoughts
prevail... John-->>Alice: Great! John->>Bob: How about you? Bob-->>John: Pretty Good!