They're almost the same thing, however, soul is a much more personal thing and a little bit more 'defined' than a spirit is. For example: There is a spirit haunting my house!/My soul will stay in this house and haunt you!

In ordinary U.S. usage, which is based on a Judaeo-Christian viewpoint, "soul" means the immortal soul that human beings are said to have. A person holding this belief system might say: "The soul is the essence of the human. It is the real 'me.' My soul temporarily inhabits my body and lends it life and movement while I live. When my body dies, my soul continues on. God will judge my soul and decide whether to send my soul to Heaven or Hell." "Spirit" is a complicated concept. It is more general, and is not limited to Judaeo-Christian belief. "Spirit" always means "something that is not solid or visible." The word "spirit" is connected to the idea of "breath," as in words like "respire." Breath is not solid or visible, and before 1600 it wasn't understood scientifically as a gas. Of course there was a connection between "breathing" and "being alive." People saw that living things breathe; on dying, there is sometimes a "last gasp" or exhalation. It was thought that the "spirit" of the human or animal was what made it live and move, and that the dying gasp was the "spirit" leaving the body, perhaps to live on in some way. "Spirit" also carries the idea of god-like beings who are not solid or visible. The use of the word "spirit" tends to refer to religious ideas that are outside the scope of Judaeo-Christian religion, and, sometimes, outside of the concept of a deity or God. Thus, one might refer to the "spiritual beliefs of Eastern religions." Yet another use is connected to the idea of "spirit" as "something that animates and gives life." It can mean vigor or enthusiasm. At a high school football game, loud cheers show "school spirit." You can praise someone for exceptional effort by saying "That's the spirit!" Alcohol is volatile, and alcoholic beverages "exhale" alcohol into the air. (We are told to leave a wine bottle open to "let it breathe.") So in yet another use of the word, "spirits," short for "spiritous liquor," can mean "an alcoholic beverage."

In scholastic theology, every living being has a spirit. The unique kind of spirit that a human has is a soul. Only humans have souls. There are other schools of thought.

The word "soul" derives from the Christian religion. Your body will die but your soul will live for ever. The word "spirit" is less religious, but indeed refers more or less to the same thing as "soul" : something not visible, but real.