what is the difference b/n ethiopian orthodox church and coptic?

Answer 1

The Coptic Church who separated Christianity in Ethiopia and established the Ethiopian church there and since then the Ethiopian church was a fellow to the Coptic church and her patriarch .

until the 1990's where the Ethiopian church asked for Independence and the Coptic patriarch agreed and now it is independent church

But if you are asking about the difference in the faith, there is no difference at all.