1. Deployment and Hosting: Plotly primarily focuses on interactive data visualization in the form of charts and graphs that can be embedded in websites or applications, while Streamlit is specifically designed for creating interactive web applications with custom interfaces for data exploration and analysis.
2. Ease of Use: Plotly requires a higher level of coding proficiency to create complex interactive visualizations, whereas Streamlit provides a simpler, more streamlined approach by allowing users to build interactive applications using Python scripting.
3. Real-time Updates: Streamlit offers immediate real-time updates to the interface based on changes in the underlying data, making it suitable for scenarios where live data visualizations or data-driven applications are required, while Plotly's updates may not be as instantaneous.
4. Community and Support: Plotly has a larger user community and support resources due to its broader focus on data visualization solutions, while Streamlit has a rapidly growing community with a focus on streamlined web application development.
5. Customization Capabilities: Plotly provides extensive customization options for creating intricate visualizations with specific design requirements, while Streamlit offers a more limited range of customization but excels in building quick and functional interactive applications.
6. Integration with Machine Learning: Streamlit offers seamless integration with many popular machine learning libraries like scikit-learn and TensorFlow, allowing for the easy creation of data-driven web applications with machine learning models integrated, while Plotly primarily focuses on visualizing data rather than directly integrating with ML frameworks.

In Summary, Plotly excels in creating interactive visualizations for embedding in websites, while Streamlit is tailored for rapidly building interactive data-driven web applications with a focus on simplicity and real-time updates.