Nationality is the legal relationship between an individual human and a Nation state. Nationality normally confers some protection of the individual by the state, and some obligations on the individual towards the state. What these rights and duties are vary from country to country. National identity is a person’s subjective sense of belonging to one state or to one nation. A person may be a national of a state, in the sense of having a formal legal relationship with it, without subjectively or emotionally feeling a part of that state. Conversely, a person may feel like he belongs to one state without having any legal relationship to it.
If there is one thing that really riles me up, it is arguments about Nationality. Many people get Nationality and National Identity mixed up. I am British through and through - that is my legal Nationality - but there are four countries that make up Great Britain, and from those my National Identity is Scottish. I have lived here in Scotland for the past 11 years (the majority of my life), all of my family heritage is Scottish, I have a Scottish surname and I was taught at school about Scottish history, how to Highland Dance and I know how to Scottish Ceilidh dance. But it is painstakingly common for people to tell me that I am English purely because I was born there; nothing will ever anger me more than another person telling me what my national identity is.
My nationality is British but my national identity is Scottish.