What does it mean when turn car on a oil light stays on for few seconds and then shuts off?

The oil light come on if there is not enough oil pressure. When you first start up, the oil pump needs a little time to build up the pressure. However, you should check that the oil reservoir is full with the dip stick (with the car cold and on level ground).

It may also be that the oil and oil filter were not actually replaced properly at the car's last service, so that the oil is thick or the filter is clogged and this is delaying the build up of pressure. To be on the safe side you could have the oil and filter changed.