Probation is condition imposed in a criminal sentence that allows creates a reduced liberty interest allowing a person to stay in the community rather than serve time in jail as long as he or she complies with certain conditions (like regularly reporting to a probation officer, refraining from alcohol and drugs, holding down a job, not associating with certain people and not committing further crimes).
Parole is the supervised release of a prisoner from incarceration into the community after a period of imprisonment at a State prison. Conditions of parole are often similar to those of probation and the officer supervising either class of offender is referred to as a probation and parole officer.