Cilantro and Coriander are really the same thing because both Cilantro and Coriander come from the same exact plant as each other.
However they do have different tastes from each other so that's the difference between Cilantro and Coriander.
Coriander has a better taste to it than Cilantro.
Coriander tastes sweet and toasty and has a warm aroma and flavor while cilantro tastes sorta of like soap or even dirt.
If you need to use either Coriander or Cilantro in a recipe then I would recommend you use Coriander to give the food a better taste.