First of all, Larry, you are incorrect.
Probation is given in lieu of prison/jail time. It is a lesser punishment where someone convicted of a crime (not necessarily a felony) would be kept under tabs where in they would need to check in with their probation officer, pass drug screens, and usually do community service as well.
Parole is given to someone who has already been in prison (almost always felons) and is being conditionally released. These people usually have to EARN their freedoms. Usually starting out in a halfway house, getting placed in a job by their parole officer so that they can be kept track of. Then they gradually work their way out of the halfway house to living at home or in their own apartment, usually with an ankle bracelet.
In both cases failure to follow all the rules of the probation/parole will usually lead to their sentence being completed in jail/prison.