What did Roosevelt mean when he said " the only thing we have to fear is fear itself?"

Franklin Delano Roosevelt made this statement as part of
his first inaugural address. He made the statement in an attempt to calm the panic and
hopelessness that had gripped the American people because of the Great Depression. The
worst days of the depression were actually the period after Roosevelt's election and
before he was sworn in, when more banks failed than at any time during the depression.
This time is commonly called "the interregnum of
despair."

Roosevelt saw that panic and hopelessness were
everywhere, and the first step in relief and recovery from the Depression was to calm
the American people. To follow through on his comment, his first act as President was to
close all U.S. Banks for a "bank holiday." Before they reopened, he conducted his first
"fireside chat," in which he asked people to imagine he was sitting in their living room
by the fire, having a heart to heart talk. He began his first fireside chat by saying in
a calm reassuring voice, "My friends, I want to talk to you about banking." His policy
worked. The next day, over 4/5's of the nation's banks re-opened, and there were no more
runs.