The decision in a court case is referred to as the verdict. An acquittal is one possible verdict in a criminal court case. It means that a person is not guilty of whatever crimes of which he has been accused.
When a person is accused of a crime, both the accuser and the accused have opportunities to present their sides of the case during a trial. Once all of the testimonies have been heard and all of the evidence has been entered, a final decision usually needs to be made. In cases where there is an acquittal, the final decision is that the accused is innocent.
A jury is not required for a person to receive an acquittal. There are many non-jury trials. When this is the case, a judge passes the verdict.
An acquittal offers a person protection from double jeopardy. This means that he can never be tried for that same case again. However, an acquittal does not offer him protection from the exact charges being entered against him if it is believed that he committed new acts.
For example, consider a man named Paul who is accused of robbing a woman named Cheryl on March 1, 2009. If Paul is tried and receives an acquittal, he never can be tried again for robbing Cheryl on March 1, 2009. This is true even if solid proof that he is guilty surfaces sometime later. If Cheryl is robbed on December 13, 2009 and Paul is suspected, he may be charged and brought to trial for this new incident.
An acquittal is supposed to clear a person of all suspicion and any pending consequences that would have accompanied a guilty verdict. The law cannot actually erase doubt from the minds of everyone, but it can force certain entities to act as if suspicion has been erased despite true feelings. This means that if the person was incarcerated during the trial, he should be released once he is acquitted. It also means that if a person is suspended by his employer pending the outcome of his trial that he should be reinstated to his former position.
The infamous O.J. Simpson trial is a good example of the type of security that an acquittal does not offer, which is protection from civil damages. Even if a person is deemed innocent in a criminal case, he still can face civil lawsuits pertaining to the same incident. Simpson was acquitted of murder by the criminal court, but was found liable for damages in civil court.