Difference Between Satin Stitch And Darning Stitch

Can someone tell me difference between Satin Stitch and Darning Stitch.

To me they both look alike.

However in tutorial for making Phulkari, commenters and saying lady is making Satin Stitch rather than Darning Stitch (which is traditionally used to create Phulkari).

And commenter is saying that lady is wasting thread by sewing on the back.

I wish to make Phulkari that is double-sided.

Please help me. I am very confused.

Tutorial,

 

Now I see


I do prefer satin stitch as I want double-sided stole.