License suspension can be triggered two separate ways
1. A conviction in court for a DUI (Vehicle Code Section 23152 (a) and/or (b)) will result in the suspension of your California driver's license. Note, if your case gets reduced to a "Wet Reckless" (Vehicle Code Section 23103/23103.5) then your license will not be suspended unless you have prior alcohol related offenses.
2. The DMV takes action through their administrative process and you lose your DMV hearing resulting in the suspension of your California Driver's license.
When you get a DUI you find yourself fighting two battles, the court and the DMV.
When you are arrested for an alcohol DUI in California you must fight off both the court and the DMV if you want to avoid suspension of your California driver's license. If you are convicted for a DUI in any California Court then that information must be sent to the DMV and they in-turn will issue a suspension based on the conviction in court.
Additionally, if you request your DMV hearing in a timely manner (A 10 day time limit is imposed) then you may challenge the suspension of your driver's license through California DMV's administrative process. Even if your case is dismissed in the criminal courts your license may still be suspended if you do not prevail at your DMV hearing.
The rules at court are not the same as the rules at the DMV hearing. The court process is a criminal process for which you are guaranteed certain constitutional rights. The DMV, on the other hand is NOT a criminal proceeding and you do not have the right to have state appointed council to represent you at the DMV hearing. Additionally, in court you cannot be convicted unless the state proves that you are guilty beyond a reasonable doubt, our highest standard. Yet, at the DMV hearing the government must only prove their case by, "a preponderance of the evidence". This means, "More likely than not" or anything above 50 percent. You can choose to represent yourself at the DMV hearing however it is highly technical and difficult even for an attorney who has not had specific training and experience with the California DMV Administrative Per Se process. I do not recommend that you represent yourself at the DMV.