Whenever people talk about ghosts and spirits, they usually think that these two things are the same. Ghosts usually stay where they have died. This is why there are some ghosts that are left behind in some houses or why there are a lot of ghosts that can be found in hospitals.
Some of them cannot accept the fact that they have died. Spirits will have a tendency to travel from one place to another. Some say that all living things have spirits, and they usually wander free when they feel that it is necessary for them to go from one place to another.
It is sometimes easy to think that these two are the same, but the slight differences will allow you to distinguish one from the other.