Spirit vs Soul

One of the definitions of spirit by Merriam-Webster goes like this: "an animating or vital principle held to give life to physical organisms."
The definition of soul is: "the immaterial essence, animating principle, or actuating cause of an individual life."

What's the difference?

I was watching a sermon by Michael Todd from Transformation Church a couple days ago and it sounded like he was separating the two terms. The definitions given by the dictionary make it sound similar right? I even used the words interchangeably and thought of them as synonymous with each other.

Okay, I studied the definitions a little more.

Spirit can also be defined as a "temper or disposition of mind or outlook" and something that can "influence a person"; soul is "a person's total self" and the "moral and emotional nature of humans."

So, in the context of me, my spirit can be altered (can be high and low, I can be happy and sad) while my soul is who I am as a whole. Souls can also be related to the human race as a whole. At least, that's what I'm interpreting it as.