Historical means ´existing or happening in the past �, ´describing events or people from the past �, ´based on the past �, ´involved in the study of the past �.
a historical figure (person)
a historical novel
Historic means ´important in history �: the historic moment when the Berlin Wall came down �, the historic meeting of the two presidents.
Historic can sometimes be used in place of historical meaning � existing in, happening in or relating to the past �, but historical should never be used in place of historic.
To me there isn´t a lot of difference. It depends on the context and who is making the statement.
Learning English is difficult but I keep trying.
It is difficult to learn English but a good teacher can help.