Hoover was a typical Republican who kept hands off business and fought against any restrictions on business.
Hoover's response throughout his administration was that there was nothing wrong, the economy was still strong, and that "prosperity was right around the corner." The 20-25% unemployment figures belied that, of course.
Roosevelt, on the other hand, felt that the Federal government had a duty to the citizens to try and use the power and money of the federals to help the common man. Hoover kept insisting that the federal government had no such duty: the states should deal with the poverty, hunger, and unemployment of the citizens. He tried hiding behind states' rights.
Roosevelt did not, but instituted practices that we might still use today, like using Federal money to build, or in today's case re-build, the nation's infrastructure such as our bridges, roadways, and locks and dams on our river systems.