Fill-opacity
<path style="fill-opacity:0.25">
- Any value between 0 and 1
- Determines whether an element is solid or transparent
- 1 is completely opaque
- 0 is completely transparent
- stroke-opacity
- opacity of strokes same as fill-opacity but applied to strokes
- opacity
- opacity applied to the element or group of elements as a whole after the fill and stroke opacity