Path is represented with the icon.
Path is a property available for both Line and Polygon.
Since 2018.1, when using the Line Mark type, clicking on the Path button opens a menu where you can select the Line type: Linear, Step, or Jump. Here's an example of a Step Line:
This property allows you to choose the order to connect the Marks. You can use either a Dimension or a Measure.
It's quite rare to use this property. Usually, you only use it if, in your data, there is a special order to connect the Marks to create a specific visualization.
The next and last property only exists for Pie.