How did Asagai define "idealists" and "realists"?

According to Asagai idealists are those people who accept changes and also dream to bring that change. Realist are those people who think regarding the future.

Explanation:

From the play A Rasin in the Sun written by Lorraine Hansberry where Joseph Asagai is a Nigerian student who has described idealists and realists in a different way. According to him idealist are considered as those person who accept changes as well as try to fulfill their dreams so that they can bring the change. On the other hand realists are those people who think practically that is they look forward towards future rather than focusing on dreams.