A buyers market is when the sellers outnumber the buyers.
In property this is caused by various economic factors, interest rates being one of them. Alternative investments competing for the same dollar, exchange rates in various sectors (eg import/export), industry closures and redundancies, relocations, commodity prices etc etc can all cause discrepancies between the number of buyers and sellers.
Such discrepancies may only affect certain sectors, they may be geographically isolated or across the board. In a buyers market properties will tend to remain on the market for longer periods, you have better negotiating power and more choice but at the end of the day the figures still have to stack up.
Cheers
Jeff