The defendants are usually the ones who benefit from plea bargains. Often they will plead guilty or enter into a plea bargain to reduce the amount of time they will be incarcerated or reduce the severity of their punishment. The plaintiff does benefit from plea bargaining though because they would not be required to go to court and there would be no hearing.
Trials can take days, weeks or sometimes months, while guilty pleas can often be arranged in minutes. Also, the outcome of any given trial is usually unpredictable, but a plea bargain provides both prosecution and defense with some control over the result.
For most defendants, the principal benefit of plea bargaining is receiving a lighter sentence for a less-severe charge than might result from taking the case to trial and losing. In addition, defendants who are represented by private counsel can save a bundle on attorney fees by accepting a plea bargain. It almost always takes more time and effort to bring a case to trial than to negotiate and handle a plea bargain.
There are other benefits as well:
Getting out of jail. Defendants who are held in custody - who either do not have the right to bail or cannot afford bail, or who do not qualify for release on their own recognizance - may get out of jail immediately following the judge's acceptance of a plea. Depending on the offense, the defendant may get out altogether, on probation, with or without some community service obligations. Or, the defendant may have to serve more time, but will ...
In 1020 words, this solution thoroughly discusses the concept of plea bargaining in terms of how it affects all parties involved: the defendant, the guilty and the judge, and the cons of this action.