Hello,
Well these days there is Fedora, which is the more "desktopy" distro with newer stuff in (a testing ground for red-hat), and there is Red Hat Enterprise Linux (RHEL) which is the one used in most servers, and is paid-for. I suggest Fedora for desktop use, and if you are looking into a web-server, RHEL
I suggest CentOS which is a free unbranded version of RHEL.