I decided to migrate my Windows servers to GNU/Linux. Which distribution should I choose CentOS or Fedora?
Short answer: CentOS.
CentOS is an enterprise ready operating system built from sources provided by a prominent GNU/Linux operating system provider: Red Hat (CentOS is a RHEL rebuild).
The release cycle of new CentOS versions is every 2 years and every 6 months it performs an update to the existing version, with the main purpose of supporting new hardware, which allows establishing a robust GNU/Linux environment (security, reliability and stability ).
CentOS only includes well-proven technologies which also contributes to its stability.
Each CentOS version is maintained (packages update) for a period of 7 years.
Fedora Linux is part of the Fedora Project, a project sponsored by Red Hat. Fedora Linux is a general-purpose operating system that has among its objectives: to be a leader in the use of bleeding edge technologies, short release cycles for the new version, one version each 6 months. Fedora Linux put great emphasis on usability in order to be easy to use, including by the newcomers on the other hand for the Fedora community it is better to update than to maintain therefore each version of Fedora Linux is maintained for a period of 1 year, hence is better suited to office environments and desktop computers in general.