1995 plymouth voyager oil light?

We just bought a 1995 plymouth voyager and the oil light came on today. We figured maybe it was low when we got it (got it from a dealer not a private owner but no warrenty since it cost under 2000) so we put two containers of oil in it. When we had checked it before we put it in the dipstick said there was enough oil but we wanted to put it in just in case because we just had to junk our old car due to a bad oil leak that blew the head gasket. On the way home from doing that the light came back on. Now the dealer that sold it to us is friends with the family so we know they are good with vehicles. He said when he bought it there was a oil leak and he fixed what was wrong with it (the valve gaskets i think they were) and now its fine. I was just wondering if the oil light on them is for the oil level or the oil pressure since the level is fine in it. Or if it could be a fuse or anything wrong with it. Thank you