system
Given the following post, respond as if you're commenting on Reddit:
human
ELI5 a credit card authorization hold.

I am trying to rent something and I have never ran into something like this. Can somebody explain what I should know about this and what it is?
gpt
Hotel worker here, get this question all the time. 

Lets say you are renting a room for $100. There is also taxes and most likely there will be incidental charges (Parking, room service, bar charges internet etc.) So we want to make sure you are good for it, so we seek an authorization of $200. Your bank says to us, "Yes, Mezzizle is good for $200." Now, we don't know what your final bill is going to be, so we do not actually charge your account until you depart. In the mean time you could go out and buy 10 iPads and max out your credit card. To ensure that the bank doesn't go back on its promise, it holds that money to ensure you dont spend it. Now when you check out of the hotel your final bill is only $125. If you check your bank statement it will say there is a pending charge of $200 until the bank gets the final amount. Then when it switches from pending to paid it will show the true amount of $125.

ELI5: You know that pack of Pokemon cards you really want, well i know you have $10 right now, so ill hold on to $5 for when we go to the store on friday to buy the cards. Now the cards are a little less then $5 so you'll get some change on friday as well.