Is schizophrenia paranoia or multiple personalities?

Schizophrenia is NOT multiple personalities. Multiple Personality Disorder (now called Dissociative Identity Disorder) is a very different illness. "Paranoia" can be a component of Schizophrenia. Persecutory (paranoid) delusions are a common symptom of Schizophrenia.

i would say neither. it is more a delusional state of mind which i guess paranoia can fit into but its definately not multiple personalities
Schizophrenia is a mental disorder characterized by impairments in the perception or expression of reality, most commonly manifest as auditory hallucinations, paranoid or bizarre delusions or disorganized speech and thinking in the context of significant social or occupational dysfunction.

Multiple Personality Disorder is a condition where a single individual evidences two or more distinct identities or personalities, each with its own pattern of perceiving and interacting with the environment. It is believed that at least two of these personalities may routinely take control of the individual's behavior. There is also some associated memory loss, which goes beyond normal forgetfulness, often referred to as "losing time".
its paranoia or what people call personality disorder. Multiple personalities are very uncommon and if you have it the likely hood you will only have one or two other personalities.
Paranoia is a type of delusionn which you think people want to harm you.

Many people with schizophrenia have delusions - ideas contrary to fact - but not all of them have paranoid delusions.

Other symptions of schizophrenia include hallucinations (e.g. hearing voices), disordered thinking and lethergy. The symptoms vary form one person to another.

Multiple personalities are part of a seperate and quite rare disorder.
Schizophrenia is not multiple personalities rather it is a condition where the mind is split from reality. It cannot distinguish what is real and what isn't making the person have delusions. These can be but may or may not include both-visionary and auditory hallucinations. Symptoms may include: paranoia, disorganized thinking, social isolation, lack of motivation. These are just a few symptoms and not all are present with a person suffering from this mental disorder. Also, these symptoms need to be present on a person for more than 3-6 months for them to actually be diagnosed with schizophrenia.
Schizophrenia is more related to paranoia than it is to multiple personalities. Schizophrenia is actually a brain disease that causes individuals to hear internal voices, to feel like they are being stalked or that their mind is being read by others, etc.

Multiple Personalities, on the other hand, is a persons "personality" suddenly changing. There may be names for these different personalities, and each one will have it's own characteristics. It's like several people living inside one body.

The big difference is that - generally speaking- schizophrenia is a disease that a person is born with (even though symptoms don't usually show up for many years), and it can be treated but not cured. Multiple personalities, on the other hand - generally speaking - is caused by excessive trauma such as severe child abuse. It is the brains coping mechanism that enables the person to survive the abuse by "leaving" and letting "someone else" experience. It can stay with a person throughout their life (even long after their abuse is over), but it can also be treated in a lot of cases.