What's the differece between korkeakoulu and lukio?

[weijie]

What group of people are going to korkeakoulu, and what's the difference with ammattikoulu?

[Upphew]

http://en.wikipedia.org/wiki/Education_in_Finland
upper secondary school = lukio
vocational school = ammattikoulu
polytechnic = ammattikorkeakoulu
university = yliopisto and universities that focus on technical studies has been called tekninen korkeakoulu