Plotly is an interactive, open-source visualization library for Python that creates publication-quality graphs with minimal code, while Dask is a flexible parallel computing library that scales Python data science workflows from single machines to clusters. Together, they form a powerful toolkit for modern data analysis: Plotly excels at transforming data into compelling visual stories with interactivity built-in, while Dask enables you to handle datasets larger than RAM by intelligently chunking and parallelizing computations. The key mental model to keep in mind is that Plotly operates on computed results (whether from pandas or Dask), while Dask operates lazily—building a task graph that only executes when you explicitly call .compute() or .persist().

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