No, you are confusing two kinds of juries. A grand jury is more informal (jury members can ask questions, etc), one sided, and secret. Defense is not presented. The prosecutor is trying to get a group of people to agree that a crime was committed and that there is evidence for a conviction. The prosecutor can skip this step or ignore the grand jury, but it's a kind test trial. If you can't win a one sided case, you're unlikely to win in a regular trial.
If the grand jury hands down an indictment, then there is the regular jury trial you are familiar with from the movies (though much more boring and procedural).