Both probation and parole are forms of supervised release, they are just granted under different circumstance:

• Probation is a sentence that is an alternative to incarceration at the time of pleading guilty; granted by a judge.
  • Typically granted to first time offenders
  • Conditions of probation include consistent check-ins with a probation officer, must stop any other criminal activity, and possible drug testing, therapy, or community service.
  • Violating probation conditions may lead to serving the original prison sentence.  
• Parole is a conditional release from prison when you are on good behavior during your prison sentence; granted by a parole board.
  • Conditions of parole include consistent meeting with a parole officer, must follow specific rules such as curfews, drug tests, and employment, and you must stay in designated areas.
  • Failure to follow these conditions may lead to being sent back to prison