in general it means you have hallucinations, delusional thoughts or other lapses in reality.....

examples....

hallucinations....

seeing things that are not real, can not possibly be real like when I thought one of my dead relatives was standing before me and other times with in my head talking to me because of a new medication I was on.

Hearing things that are not real can not possibly be real like hearing someone walk around my home when Im the only one at home. hearing the phone ring when it did not (if it had the caller ID would have registered a phone call) hearing people talking about me when in reality they are not......

smelling baked apples or other odors when there is no real base for it.

the taste of onion but yet not real because I am not eating anything containing onion at that moment...

delusions.....(delusional thoughts, beliefs...)

holding the belief that all men are bad just because a few harmed me.
thinking others are out to get me when not on medication for my bipolar
thinking people can read my mind when not on medications for my bipolar and because of certain types of meds /herbals and vitamin supplements.
Losing time when its part of my bipolar or PTSD or sleep issues rather then my dissociative issues..

mind you these are just examples that sometimes happens to me... because people react differently and each location, culture, religion, treatment providers,......all have different ways of understanding and defining mental health terms this may or may not be what your own treatment providers go by and may or may not be what your own body and mind goes through when you are psychotic (lose touch with reality.)