If it is a drain, and there is no trap, then that is also a problem. The point of the trap is so some water stays in it and blocks off vapors from the sewer. We had an issue in our house where at certain times of the year it would smell like sewer in our house. Turned out there was no trap at the sump! Pewww
ok...its a floor drain. Its there to catch any large water spill onto the basement floor like from say a failed water heater. Seeing liquid in it is NORMAL. If there was no water in it, it would smell like open @$$. I swear I cant believe the home inspector didnt tell you what it was. These are common.