So Arch is a rolling release based distro and gets package updates as they are released upstream.
Whereas Fedora is on a stable release model where core packages are updated every ~six months and each release is supported for ~13 months. Note that you still get security bug fixes but these are often patched into current versions of the software rather than upgrading to the latest version unless absolutely necessary.
It’s often said that due to having a rolling release model Arch new packages could cause issues not identified by the limited testing time, personally I haven’t experienced any in my use of Arch. However there was a semi-recent issue with a kernel update causing data loss which is a concern.
Two reasons I particularly like Fedora is that some packages such as the kernel and applications are updated following the upstream release model (with a longer testing period compared to Arch) which I don’t think is the same for other release based distros such as Ubuntu and Debian. The second is that I see Fedora as pushing the Linux desktop forward with supporting the development and implementing new technologies.