There are two important words in the party’s name. These are “national” and “socialist.” There is a different reason for each to be in the name.
Socialists are people who want there to be more economic equality in a country. They want money to be taken from the rich and given to the workers. They want the workers to be in control of the places where they work. They do not think it is right for the people who do not do the physical work (company owners and executives, for example) to get the lion’s share of the money. The Nazi Party started out with some socialist roots. It was a workers’ party that felt that workers were being exploited by the rich. This is why the word “socialism” is in the name.
Nationalists are people who believe that their kind of people is superior to other kinds of people. In the case of the Nazi Party, this meant that they believed that ethnic Germans were superior to people like Slavs and, especially, Jews. Because the party believed this, it was a nationalist party and used the term “national” in its name.