Can some one please explain the actual function of the rate syntax
=RATE(nper,pmt,pv,fv,type,guess)

From what i understand this tells me that over a certain amout of years of
paying off the loan amount it gives me a interest rate monthly and yearly.
but it is not to clear, How come the interest rate changes and if i dont put
the minus symbol in the monthly payment cell the outcome is NUM#.
This is really confusing and the help menu doesnt explain this syntax very
well

PLEASE HELP