What are delusions and hallucinations?

I'll explain: Delusions are when you think something is happening and it's not. For instance you may think you're the president of the United States, but you're not. That's a delusion (unless you're an african american senator from illinois). A hallucination is where you sense something that's not there. It can be something you think you smell or see for example that's not really there.

Delusions/Hallucinat: Delusions are false beliefs. Hallucinations are false perceptions.

Different : A delusion is something that can theoretically happen, but is not very likely. An example of this would be, when a patient tells me that Cindy Crawford is in love with him. That's a delusion. A hallucination is, by definition, any one or more of the five senses interpreting stimuli from the environment that does not in reality exist.