Not familiar with OH, but I have bought a couple properties in IN at Sheriff sale as recently as a couple years ago. These are typically foreclosures and there will usually be a judgement against the property from the bank, amount is typically listed in the public advertisement. If the bank thinks they can sell the property at a decent profit above what they are owed (the judgement amount), they will often have a representative at the sale and bid on it, take possession, then clean it up and sell it. If the property is in poor shape, the banks often don't see that they will ever get anything $$ back worth their while, so they will let it go to the highest bidder at sale. I bought our last one for $1 over the judgement amount.
If you are the winning bidder, you will then have XX days to pay the county and get title on the property. If you need to borrow money, you will want to line that all up in advance, because the required payoff time is pretty quick. You will also be responsible to get any delinquent taxes paid current. It's wise to spend a little $$ and have a local title company do a title search ahead of time to make sure there are no other judgements against the property, as you would inherit those when you take title.
Complete different deal from a tax sale. On tax sale it is there because taxes are long overdue. You bid on the property, and pay the taxes current right away. The original owner typically then has 12-24 months to get caught up on the taxes before you would take possession. If they get the taxes caught up and pay you and the county some small fees and interest, they get their property back. If they don't it get's deeded over to you.
Usually someone at the sheriffs office and / or the county recorder or assessor can explain pretty clearly how all of this works. Your local title company is also a good resource to learn the ropes.
Good luck !