There are two versions. One is that it's the same thing. The other - and many christians and buddhists hold the same view - is that soul is your mind, will and emotions. Your spirit is the part of you that connects with the spiritual world and includes conscience, intuition... We connect with the material world through our body's five senses. We connect with the spiritual world through our spiritual senses.
I believe humans all have a soul, but once we pass, our souls become spirits as we take on our "true form" I suppose.
Souls don't exist. I can buy spirits at Trader Joe's.
You don't exist.
Your soul is your morals. Your spirit is your tenacity. More or less.
Think about it. When the subject of a person with no soul comes up, he/she is more often than not a murderous sociopath. When someone has no spirit, they're usually depressed and lose all ambitions.