Probation is widely used in Juvenile Court, as you might expect in a court where the primary reason for its existence is the rehabilitation of the youthful offender. The point usually is not just to dump the offender into juvenile detention, but work with him or her and the parents to resolve the issues that got him in trouble.
When a juvenile is found by the court (no right to jury trial here) to be "guilty" of the charged criminal offense, the Judge sustains the petition and gains jurisdiction over the juvenile's life, in very extensive ways. Juvenile Probation will have many terms and conditions in common with adult probation, such as requirements that the offender obey all laws, work to pay restitution to the victim, report to the officer, get the Officer's permission for any change of address or job, and attend counseling or remedial classes for anger management, alcohol abuse, or drug abuse.
However, the Juvenile Probation Officer's repertoire of tools is much broader than that. He can require the juvenile to attend a special school for problem youths so he or she gets specialized attention. He may be released to his parents with strict controls set not by the parents, but by the Probation Officer. These may include a curfew, strict bans against any association with specified individuals (and certainly with gangs), maintaining a job, reaching certain academic goals, and almost any other rules and limits that good parenting might impose in the first place. It is in a real sense that a juvenile becomes a "ward of the court," as he virtually gets a new parent.
Suppose a juvenile gets into trouble, but his involvement was not overly serious, his parents seem capable and level headed, and the police do not feel that a full petition for wardship is necessary. In that case, they can bring the juvenile before a Juvenile Probation Officer for initial intake and counseling. The Officer may just talk to him or her with the parents present, or assist them in maintaining better control over their child. This is not actually being "on probation," but it is useful and sufficient in many cases and avoids bringing the juvenile into the legal process.