Penal Code section 245(a)(1) means assault with a deadly weapon (not a firearm) with great bodily injury or with force likely to cause great bodily injury. This can be a felony or a misdemeanor based on the facts of your case.
If it is a felony, the maximum sentence prescribed by statute is 4 years. If it is charged as a misdemeanor, the maximum sentence would be 1 year. There are other factors as well, i.e. previous criminal record, etc.
Contact a local criminal defense attorney who can sit down with you and speak with you over your prior criminal record if any, and the possible charging allegations (felony or misdemeanor), possible defenses, etc.
If filed as a felony, based on the "Great Bodily Injury" indication, it can carry up to 7 years in state prison and a Strike under CA's 3 strike laws (up to 4 years for the charge + 3 years for the personal infliction enhancement allegation), and be a presumptive prison case.
The individual facts of the case and the severity of the conduct/injuries will determine what is filed and what the realistic exposure in custody is.
This person should be consulting with a locally experienced criminal defense attorney who should be able to give a more detailed assessment.
The answers above correctly describe the charge and what it means. Anyone facing this charge should consult with an experienced criminal defense attorney right away. Most provide a free consultation.
If the person facing this charge cannot afford his or her own attorney, they will be assigned a public defender at court. Many public defenders are wonderful lawyers, and it is always very important to be totally open and honest with one's lawyer.