When combined, 开 (open) + 朗 (bright) = 开朗 (kāilǎng) creates a powerful metaphor for a personality. A 开朗 person has an “open and bright” disposition. Their heart is not closed off, and their spirit is not dark or gloomy. They are emotionally transparent and full of light.
In Chinese culture, having a 开朗 personality is considered a major virtue. It goes beyond simply being an “extrovert” in the Western sense.
开朗 is used almost exclusively to describe people and is always a compliment.