The arraignment is the first time the defendant appears in court.
At the arraignment, the judge tells the defendant:
What the charges are,
What his or her constitutional rights are, and
That if he or she does not have enough money to hire a lawyer, the court will appoint a lawyer free of charge.
The defendant may then respond to the charges by entering a plea. Common pleas include guilty, not guilty, or no contest (also known as nolo contendere).
Not Guilty means the defendant says he or she did not commit the crime. Sometimes, defendants enter a plea of not guilty as a strategic decision during plea bargaining or because they want to go to trial and force the prosecution to prove its case beyond a reasonable doubt.
Guilty means the defendant admits he or she committed the crime. The judge finds the defendant guilty and enters a conviction in the court record.
No Contest means the defendant does not contest (disagree with) the charge. This plea has the same effect as a guilty plea, except the conviction generally cannot be used against the defendant in a civil lawsuit.
If the defendant is in custody at the time of arraignment, after the defendant enters a plea (responds to the charges), the judge will:
Release the defendant on his or her own recognizance (which means the defendant promises to return to court on a specified date), OR
Set bail and send the defendant back to the jail until the bail is posted, OR
Refuse to set bail and send the defendant back to jail.
Bail is money or property that a defendant puts up as a promise to return for future court dates. When setting the amount of bail, the judge takes into account the seriousness of the crime, whether the defendant is a risk to the community, and whether he or she is a flight risk and likely to run away.
http://www.courts.ca.gov/1069.htm