三皇是一般是指伏羲，神农氏，燧人氏，五帝指的是黄帝，颛顼，帝喾，尧，舜

some earliest leaders of china, who have been recorded by some books.

It's a conceptual noun. You can search it on Internet and 百度（a Chinese search engine）can give you a quite right answer.But in terms of “name”,some are real but some are tale.

3 Sovereigns and 5 Emperors is a period of chinese history before the Xia period. It covers 2000-3000BC. The Wikipedia entry Three_Sovereigns_and_Five_Emperors gives a useful introduction.

是后人对远古时期的帝王的统称。具体指哪些帝王有不同的说法。