The block settings sidebar (everything in the right column when editing) lets you configure individual block instances. This is different from the styles sidebar, which affects global styling across your block theme.
Most blocks have visual settings only, but some blocks like images have a split interface with both Settings and Styles tabs. The Settings tab controls functionality (like alt text), while Styles handles visual appearance.
Understanding this distinction is crucial for block theme development because some settings affect both functionality and visual appearance. For example, enabling content width in a Group block changes how it works but also impacts the visual layout.
The key insight? Block settings are instance-specific, while the styles sidebar affects your entire site’s design system.