They’re PHP extensions. As KonstantinDK mentioned, you’ll need them to run Magento. They’re also listed on the system requirements page. You can use the attached script to see what else (if anything) you need to run Magento. If your hosted by someone else, ask them to install whatever is listed when you run the attached script. If they won’t install it, you’ll need to find another hosting company who supports Magento or who will install those for you. If you’re on your own server, then it’s easy enough to install these extensions.