I recently took a course in Wholesale Buying. For the life of me, I can not understand how owner financing works. Can this be broken down to were it makes sense to me?

Are you going to be the buyer or the seller ?

But if you are the buyer, you make an offer on their home, ( you will assume they own the property free and clear, so there is no mortgage to pay off on their part.

And you ask them to be the lender, so they hold the mortgage on the home, and you pay them instead of the bank,
Other option would be where you do a contract to purchase, the real deed stays in their name, but you pay a amount each month and at the end of the contract they sign the deed over to you. * this protects the seller more, since there is no foreclosure, if you don't pay, it merely converts to a rental, and they can evict.

And of course the option where the owner offers to hold a second mortgage, if you can not get enough on your first mortgage or do not have enough for the down payment