Schizophrenia isn't the same as multiple personalities. That's DID (dissociative identity disorder). Schizophrenia consists of some combination of the following:

• hallucinations
• delusions (weird or paranoid thoughts & beliefs that won't go away)
• disorganized thoughts
• disorganized or catatonic behavior (not responding to environment)
• "negative" symptoms, i.e. lack of functioning, including social function, motivation, speech, pleasure, showing emotion, etc.