Wholeselling, how does it actually work?

[Britney Beverly]

I'm new to being intrested in real estate. How does wholselling work. I understand that you buy a place, then find somone eles to buy it for more, then you pocket the difference. How do people buy places to begin with? Not too many people have $140,000. I heard one guy say he got money from a lender but even then, how can he pay the lender back if he only pockets the difference? Which isn't the whole $140,000?