That difference is discernment. Usually loan sharks make exuberant loans that they know their customer will not pay back so that they can constantly heckle them while also making incredible gains by putting psychological pressure on them to pay up are actually after simply controlling the recipient of the money.
Quick loan companies work usually off of your paystubs so they won't loan you something you cannot pay back if you're a reasonable human being. QLCs are like credit cards in the sense that they don't hide anything and they don't tell you it's free money it's usually a failure of the person who is borrowing to make those connections and thus why they get into trouble.
One preys on you regardless of your fiscal sensibility and the other just profits because someone's an idiot and is trying to patch their already patchy fiscal problems.
Quick loan companies loan money to desperate people at very high interest rates. They know many of their customers will have trouble repaying these loans. Although they don't break your legs when you didn't pay, they do sue you and ruin your credit rating. Though less violent, these actions last longer than broken bones.
Quick loans and loan sharks are essentially the same beast. Quick loans can help you in the moment, but without reading the fine print you don't know that the interest rates on paying them back is outrageously high. Not only interest, but the amount you have to pay back each month will land you right back where you were if you still are in debt when it's time for them to collect.
In a matter of weeks after getting a payday loan or the like, the interest owed on the loan could be more than the loan itself. These loans are also taken advantage of, mostly, by low income people who have no way to pay it back. They also use advertising that is not up front about all of the fees included in the loan.
If you have a person who needs the money and can not get it any traditional way then these are the only options. Short term they are a good thing forr someone with no credit, but with the amount they charge in interest rates once you are in it is very hard to get out and you just get deeper and deeper . I think the Government needs to have regulations on how much they can charge.
These are loan companies that offers short term loans with rates upwards of 250%. They often require holding a blank personal check of yours as collateral. They essentially require you to grant them direct legal access to your bank account. Recall that writing a substantial sized bad check is a crime. Finally, a +250% left unpaid will exponentially turn into an unpayable debt rather quickly. They are legal loan sharks, that prey on the desperate.