Usually it's very far right learning. Very nationalistic. Often it's compaired to such things as white supremacy, neo-nazism, antisemitism, and overall racism.

This quote sums it up

'alt-right' or 'alternative right' is a name currently embraced by some white supremacists and white nationalists to refer to themselves and their ideology, which emphasizes preserving and protecting the white race in the United States in addition to, or over, other traditional conservative positions such as limited government, low taxes and strict law-and-order. The movement has been described as a mix of racism, white nationalism and populism, ... criticizes "multiculturalism" and more rights for non-whites, women, Jews, Muslims, gays, immigrants and other minorities. Its members reject the American democratic ideal that all should have equality under the law regardless of creed, gender, ethnic origin or race.

I'm just pulling from Wikipedia, since I don't pay too much attention to the alt right