Lighthearted
Part of speech: adjective
Definition: Joyful, glad, taking pleasure in being alive. Not depressed or sad. Enjoyable lack of seriousness, not grave.
Example sentence: When I have had a long day at work, I want something to watch that is funny, lighthearted and easy to get into, and reality is that. I'm not really into serious programmes or documentaries.
Cheerful
Part of speech: adjective
Definition: Noticeably happy and optimistic.Bright and pleasant
Example sentence: I am determined to be cheerful and happy in whatever situation I may find myself. For I have learned that the greater part of our misery or unhappiness is determined not by our circumstance but by our disposition.