Answer:
Ethnicity is the genetic heritage of someone while Nationality is your citizenship within a country.
Step-by-step explanation:
This can be confusing as sometimes the name of ones ethnicity is the same as their nationality. For example, if you are living in Germany, you are German. Just because you live in Germany though doesn't mean your ethnically German. Take me for example. I am an American because I live in the USA, however, ethnically I am 50% British due to my ancestry.