It is an Adverb. Adverb modifies and functions like an adjective.
She studied in France on how to learn to fly.
He's hoping to convey the similarities and differences of the German government from governments of the past since that is the purpose of making comparisons.
Courage means standing up for what you believe in despite what anyone says. Courage also means not being selfish and putting others first. When a person is courageous, they aren’t just brave, they are brave enough to do the right thing. Because sometimes people don’t do the right thing because it isn’t ‘easy’ or everyone else is doing something else. Courage is standing up and speaking out. Courage is being a good person.
