No. It means the prosecutor in your case is not filing charges at the moment. The prosecutor can decide to charge the case anytime within the statute of limitations. Depending on the conduct involved, the statute can be anywhere from one year to life. I practice in San Diego County and am aware of how both the District Attorney and City Attorney operate. In a case involving a sex crime, the prosecutor may hold off charging in order to develop the case and acquire additional evidence. So you're not out of the woods yet. You should consult with a local defense attorney to see what can be done to ensure the case remains "rejected."
A dismissal only happens after charges have been filed, so if your case was never filed, it wasn't "dismissed" but just not filed.
If no charges were filed, the arrest will remain on your record, but you do not have any conviction to disclose on most job applications. If you feel you were wrongfully arrested, you can try to get this removed completely from your record through a petition for factual innocence under Penal Code 851.8. That's the only way to clear something off your record.