- Character is about integrity. A person with a cheerful personality might be honest or dishonest, hard-working or lazy, trustworthy or untrustworthy, brave or cowardly, altruistic or sadistic, generous or stingy, open-minded or hidebound.
- Personality is about outward behavior - how we present ourselves, how we act, how others see us. A person of good character can be cheerful or glum, witty or dull, introverted or extroverted, risk-taking or cautious.
As you know by now, both words have other meanings, as well. But in the sense that you're using them above, that's the difference.