Can be either conditional or absolute. Conditional discharge is used frequently for the first time minor offences. Aims to stop re-offending and deterrence by having the cavate that if re-offending occurs, a more severe punishment can be given.
Absolute discharge is rare but when no penalty is imposed. It's the lowesr level of punishment. A court believes the process and experience of being arrested, court etc is enough deterrence to ensure no futher crimes are committed.
Disadvantages
This would not work for those who do not respect the system as they would likely be back in court for re-offending