The present simple is used to describe things that we do regularly, facts, habits, truths and permanent situations.
The present continuous, be + present participle, is used to describe things that are happening at the time we are speaking, temporary situations and activities that are in progress. Stative verbs are not usually used in the present continuous.
http://www.bbc.co.uk/learningenglish/english/course/lower-intermediate/unit-2/session-2/activity-3