Expand stroke expands the stroke of a shape or line, converting the line's boundaries into paths forming a closed shape.
Drawing a line creates an open path with a skeletal structure that can be adjusted. The boundaries of a line, on the other hand cannot be edited. Expanding the stroke converts the line's boundaries into paths forming a closed shape, so you can edit them individually in the same way as a regular shape.
The expand stroke feature has a range of uses. It can be used to:
The shape's stroke is now detached from the object and made into curves. As with Convert to Curves, the resulting curves can then be manipulated with the Node Tool.