Probation is the suspension of the imposition or execution of a sentence and the order of conditional and revocable release of the convicted defendant from custody under the supervision of a probation officer.
Another words, you will not be going to jail/prison for your crime, instead you will be released with certain court imposed conditions. If you violate those conditions, you might be sentenced to jail/prison term. Probation is not a right, but an option that rests within the discretion of the court.
Under California law, probation is precluded primarily for those who commit violent crimes or serious drug offenses, or are recidivist serious offenders. The following are the most common grounds for ineligibility:
• Armed Offenders. The court may not grant probation to defendant convicted of a felony where he/she personally used a firearm during the commission or attempted commision of the offense.
• Offenders Inflicting Great Bodily Injury. The court may not grant probation to a defendant who personally inflicts great bodily injury during the commission or attempted commission of felonies specified under PC 1203.075(a). The defendant must have personally inflicted great bodily injury on the victim to be denied probation.
• Repeat Offenders. If the defendant is convicted of any felony and it has been pleaded and proven that the defendant has one or more prior serious or violent felony convicted, regardless of when the prior offenses were committed, probation shall not be granted, not shall execution or imposition of the sentence be suspended for any prior offense.
• Parolee Offenders. The court must deny probation if the defendant is convicted of a violent felony or a serious felony committed while on parole.
• Sex Offenders. Penal Code 1203.065(a) prohibits the court from granting probation to defendants convicted of certain sex offenses.
• Public Transit Offenders. A defendant who previously been convicted and sentenced for a crime committed against an occupant of a public transit vehicle or directed at the vehicle may not be granted probation or a suspended sentence.
• Aggravated Arson Offenders.
• Offenders Committing Violent or Serious Felonies While on Probation.
On a conviction of a nonviolent drug possession offense, an eligible offender must receive probation, with a conviction set aside and the charges dismissed of the successful completion of probation. The term “nonviolent drug possession offense” does not include the possession for sale, production, or manufacturing of any controlled substance.
The court may not grant probation if the defendant is convicted of a number of drug crimes enumerated in PC 1203.07.
Here, the court has discretion in granting probation. Except in unusual cases where the interests of justice would best be served if the person is granted probation, probation shall not be granted to any of the following persons:
(1) Unless the person had a lawful right to carry a deadly weapon, other than a firearm, at the time of the perpetration of the crime or his or her arrest, any person who has been convicted of arson, robbery, carjacking, burglary, burglary with explosives, rape with force or violence, torture, aggravated mayhem, murder, attempt to commit murder, trainwrecking, kidnapping, escape from the state prison, or a conspiracy to commit one or more of those crimes and who was armed with the weapon at either of those times.
(2) Any person who used, or attempted to use, a deadly weapon upon a human being in connection with the perpetration of the crime of which he or she has been convicted.
(3) Any person who willfully inflicted great bodily injury or torture in the perpetration of the crime of which he or she has been convicted.
(4) Any person who has been previously convicted twice in this state of a felony or in any other place of a public offense which, if committed in this state, would have been punishable as a felony.
(5) Unless the person has never been previously convicted once in this state of a felony or in any other place of a public offense which, if committed in this state, would have been punishable as a felony, any person who has been convicted of burglary with explosives, rape with force or violence, torture, aggravated mayhem, murder, attempt to commit murder, trainwrecking, extortion, kidnapping, escape from the state prison, a violation of Section 286, 288, 288a, or 288.5, or a conspiracy to commit one or more of those crimes.
(6) Any person who has been previously convicted once in this state of a felony or in any other place of a public offense which, if committed in this state, would have been punishable as a felony, if he or she committed any of the following acts:
(A) Unless the person had a lawful right to carry a deadly weapon at the time of the perpetration of the previous crime or his or her arrest for the previous crime, he or she was armed with a weapon at either of those times.
(B) The person used, or attempted to use, a deadly weapon upon a human being in connection with the perpetration of the previous crime.
(C) The person willfully inflicted great bodily injury or torture in the perpetration of the previous crime.
(7) Any public official or peace officer of this state or any city, county, or other political subdivision who, in the discharge of the duties of his or her public office or employment, accepted or gave or offered to accept or give any bribe, embezzled public money, or was guilty of extortion.
(8) Any person who knowingly furnishes or gives away phencyclidine.
(9) Any person who intentionally inflicted great bodily injury in the commission of arson under subdivision (a) of Section 451 or who intentionally set fire to, burned, or caused the burning of, an inhabited structure or inhabited property in violation of subdivision (b) of Section 451.
(10) Any person who, in the commission of a felony, inflicts great bodily injury or causes the death of a human being by the discharge of a firearm from or at an occupied motor vehicle proceeding on a public street or highway.
(11) Any person who possesses a short-barreled rifle or a short-barreled shotgun under Section 33215, a machinegun under Section 32625, or a silencer under Section 33410.
(12) Any person who is convicted of violating Section 8101 of the Welfare and Institutions Code.
(13) Any person who is described in subdivision (b) or (c) of Section 27590.
(f) When probation is granted in a case which comes within subdivision (e), the court shall specify on the record and shall enter on the minutes the circumstances indicating that the interests of justice would best be served by that disposition.
http://codes.lp.findlaw.com/cacode/PEN/3/2/8/1/s1203#sthash.ZneOvAAV.dpuf