Microsoft Transaction Server. Basically you create In Process components in vb or c++ or your language of your choice. What MTS does it kinda make sures that things either go all the way true or not. ie:
If RS.Update = true then
component.SetComplete()
else
component.abort()
end if

So what did this do. The update goes thru, but if for some reason the update does not occur. A rollback is performed. That means the Transaction is a failure.
another example. You want to pay with your credit card.
The money is taken out of your account to send to another system. If that system fails. You would not lose your money the transaction would rollback and return your money to your account. MTS, manages transactions. It's pretty cool. MS has renamed it to COM + and they are planning to go away from it. I do not know how, but that is what they say. I assume that you know what COM is if not. It's MS component object model. Reusable code. It's worth reading about.I hope that helped some.