What Is The Difference Between Pre-authorization And A Charge On A Credit Card?

This topic is very sensitive and some how technical in understanding. I would like to explain Pre-authorization first. In fact, Pre-authorization is evident from its name that  seller will swap your card to obtain approval from the issuing authority equal to the amount that you have spent  and expected expenses amount from your bank are secured. Then the bank will allocate an approval code and seller will get money through that approval code at the end of the purchase.

While charge on credit card means taking the money from your limit physically. For example, some one is getting a room in a hotel and room per night fare is $100, so the hotel's front desk officer will swipe the credit card and will authorize $100 against your card and bank will give a certain approval code which means that bank is guaranteeing the existence of that certain amount in credit limit, when you will check out, the hotel will charge the card to obtain that money from your bank account.
Pre-authorization will always be reflected with Minus Sign on your online credit card detail and when hotel will charge your card, the sign will automatically change to positive, means that money is taken by the hotel out of your credit line.

In our company - The account operates on a prepaid basis so the monthly fee is payment for the coming month. We require a document called "Pe-authorized payment form". That document serves as an "authorization" and "by signing" on the form, you agreed to the terms and conditions that, you authorize the company or the merchant to charge your credit card as payment for the service; and as an account holder, you are responsible for all charges incurred; and you authorize the company or payment processor to charge your credit card or debit your bank account through direct debit for all outstanding amounts.