Roosevelt served three full terms in addition to almost one more year as President, so naturally his foreign and domestic policies changed over time. I will discuss the most important aspects of each.

FDR's domestic policy was dominated by his response to the Great Depression, which was at its worst when he was inaugurated in 1933. His response, known as the "New Deal," was a collection of federal programs broadly aimed at relief, recovery, and reform. These programs represented a remarkable, unprecedented expansion of the powers and the scope of the federal government. Some, like the Civilian Conservation Corps, which put young men to work on conservation projects, were intended to be temporary "make work" programs that would be eliminated after the Depression ended. Others, like Social Security, were permanent structural reforms that persist today. By the end of the 1930s, the outbreak of World War II ended the Great Depression, and FDR's domestic priorities shifted to mobilizing the nation for war. 

World War II was the single most significant aspect of FDR's foreign policy, though other developments, like the "Good Neighbor" policy intended to foster better relations with Latin American nations, were also important. The United States took a rather firm isolationist stance toward events in Europe, much to FDR's frustration. He generally sought to promote a more active role in world affairs, advocating for the "quarantine" of aggressor nations and pushing for increased American aid to Great Britain after the outbreak of the war. After Pearl Harbor dragged the United States into war, FDR worked hard to maintain the somewhat uneasy alliance with the Soviet Union. Even as the United States fought on two sides of the globe, FDR promoted a postwar order that would include international institutions like the United Nations as well as the International Monetary Fund (IMF) to promote economic stability and growth around the globe.

So in short, FDR's domestic policy was dominated by his response to the Great Depression, and his foreign policy by his response to World War II.