Matplotlib: The Foundation
Matplotlib is Python's core plotting library. It gives you full control over every element of a chart — axes, labels, colours, legends. Most other visualisation libraries (including Seaborn) are built on top of it.
Seaborn: Statistical Plots Made Easy
Seaborn wraps Matplotlib with a higher-level API designed for statistical visualisation. It integrates directly with Pandas DataFrames and produces publication-quality plots with minimal code.
Key Takeaway
Use Matplotlib for full control and customisation. Use Seaborn for quick, attractive statistical plots. In practice, you'll use both together.