2这都是名字,但含义有别,bliss有高兴和快乐之极的意思.请看下面的解释便清楚了：
bliss
1、n.福佑,天赐的福
大写的：Bliss
布利斯(姓氏)
2、极乐,至喜;天堂之乐
They were in a state of bliss during the honeymoon.
他们在蜜月期间幸福无比.
happiness
[5hApInIs]
n.
1.愉快；幸福
After they got married,they had many years of happiness.
他们结婚后,过了许多年幸福的生活.
Queen was happiness incarnate.
女王是幸福的化身.
2.适当,恰当
3.高兴；愉快
It's a great happiness to us to have a grand banquet in your honour here.
在这儿为你们举行盛大的宴会是我们极大的愉快.