Swath width is the width of the ground strip a satellite sensor captures in a single pass; wider swaths cover more area per pass but typically at lower resolution.
Sensor design trades swath against resolution: wide-area sensors image broad strips (good for mapping large regions quickly) while high-resolution sensors image narrow strips in fine detail. Tasking a large AOI with a narrow-swath sensor requires tiling — multiple adjacent strips across several passes.
SAR satellites expose this trade-off explicitly through imaging modes (e.g. spotlight for fine detail over a small scene, stripmap for a balance, and ScanSAR for wide-area coverage at coarser resolution).
A wider swath covers your area in fewer passes; a narrow, high-resolution swath may need tiling across multiple passes to fully cover a large area of interest.
Plan a real acquisition over your area on the interactive map, browse the satellite catalog, or read the tasking guides.