What is the difference between race and ethnicity?

Putting aside for a moment that biological race doesn't exist... Race is a social construct- we separate our species into groups of race based on similarities in features. However, there is no biological basis for race. Ethnicity involves the culture, religion, and traditions of any given group.

So what is the difference between ethnicity and nationality?

Race is your color or what you consider yourself. Nationality is the country you were born. Ethnicity actually can be a combination of nationality and religion, language and culture. Religion well you can be of any nationality, ethnic group and race. For example. Lets say my parents were born in Spain and both are Jewish. Lets say I was born in Mexico. My nationality is Mexican. My race I consider myself White/Hispanic. My ethnicity is Jewish/Mexican. My religion is well Judaism.