Why do I still pay for free apps?

Another issue I'm having is even if I pay for Apple iPhone apps that are FREE, I have to have money on my card for it to download. Even if I have to update the. I don't understand it. Why is this? I thought it was all free

You don't

Free apps means you don't have to pay for it.

  • Why will Apple give an Iphone 4s free and At&T wants me to pay $99 dollars? Apple is 8Gm for free if you upgrade contract… At&T is 16 GB for $ 99 dollars. With upgrade… I'm getting a new phone… I don't want to pay 100 bucks and I/m not getting the 5 or 5S or 5C… Not spending 200 on a phone. But what phone would you get?
  • Why do people still pay so much for damanged iPhones? It's funny how pathetic some people are. I sold my cracked, dented and slightly bent iPhone 6 Plus (16GB) online for roughly $600. And because of my insurance and discounts, I was able to pick up a brand new one and had extra cash on the side, which I'll put toward the next iPhone.
  • Why do I have to pay even for free apps in the App store? I used to get free apps without any problem. Now, out of sudden, it says: Before you can make purchases, you must sign in the verify your payment info. I've been having my iPhone for half an year and it suddenly brings this up. Any ideas?
  • Why can't I pay for apps with my App Store voucher? I recently bought a £20 App Store voucher for my iPhone (running iOS 6) and, even though I entered the code and it was accepted by Apple, my phone still fails to recognise the fact that I have £20 as my balance. Instead, it asks me to input credit card information (which I didn't do, presuming that it would charge the App cost to my card as opposed to the voucher). I wondered if there was any setting to configure which way you pay for Apps etc.