Welcome to the Nationalism page ring!

Nationalism is basically to love your nation. It's often coupled with more extreme ideologies like fascism and or xenophobia (hatred or distrust of foreigners), but nationalism by itself atleast generally is harmless and doesn't hurt anyone beyond being patriotic.

Nationalism also goes beyond just one's nationality and in some places it's also tied in with religion, like in Malaysia where by definition of the Malaysian constitution a Malay, or a native inhabitant of Malaysia is a Muslim, born in Malaysia, speaks Malay and practices Malay customs. This means that technically when a Malay leaves the Islamic faith, they're legally no longer considered a Malay.

Civic Nationalism

In places like the United States which is a large melting pot of various ethnicities and races they play into civic nationalism, which is basically where (in this case) being an American is defined by adhering to the same values as others (democracy) and holding true to a common set of principles (liberty, freedom, etc.) In civic nationalism, you voluntarily belong to a nation (through naturalization/birthright citizenship) and where anyone regardless of background can become part of a nationality.

Ethnic Nationalism

Ethnic Nationalism is where nationalism is defined by where you're born. In the 19th century German Empire, a German is someone who's born in Germany, speaks German and is ethnically German. This means that a Jew who was born and raised in Germany, spoke German and lived in Germany would oftentimes not be considered German and would be excluded from the German nationality for the simple fact that they're not ethnically German. Ethnic nationalism also views as having a single, singular ethnicity state as ideal and also supports the idea of self determination (Kurdish state for Kurds, Turkish state for Turks).

It's not inherently racist but it can easily be used to justify genocide (ethnic cleansing) and give people a sense of superiority over other ethnicities.

Expansionist Nationalism

Expansionist nationalism is a more extreme form of nationalism where the right to extend the power of a nation through territorial conquest or exerting influence over other nations is seen as just. Often ties in with colonialism and people who follow expansionist nationalism see their own nation as superior to others with the right to colonize or occupy surrounding territories under their banner. This, or irredentism where one reclaims "lost" territories where one's people still live but under a different country.