First, the meaning is different.
1 happiness
It means happiness, perfection and sweetness.
Step 2 be happy
It means to feel happy or satisfied.
Second, the basic explanation is different.
1 happiness
①、? It's called blessing.
(2), make people feel comfortable situation and life.
(3), refers to life, circumstances, etc.
Step 2 be happy
When people meet happy events, a happy or satisfied state is the expression of people's mood.
Third, the citation interpretation is different.
1 happiness
Act III of Cao Yu's Thunderstorm: "We are all young, and we will definitely seek happiness for mankind in this world in the future."
Step 2 be happy
Ba Jin's Home VI: "He is neither happy nor sad". ?
Refer to the above? Baidu Encyclopedia-Happiness, Baidu Encyclopedia-Happiness