Fedora community + help of redhat company =fedora
redhat = fedora + some enterprise packages..
centos = redhat( from 2 month ago) + some new and extended packages
Fedora for user and centos for server and redhat for best server
fedora and centos dont need repository for update because have miror but rhel if you dont
have rhnetcod cant update system
CentOS should be binary compatible with RedHat Enterprise.
CentOS often lags behind a bit though - so may not have security fixes out in time - as it
takes them time to QA/ensure they've removed RedHat brandings. http://lwn.net
have had some
articles about CentOS recently - concerning the project structure and the fact they made no
real security patches/fixes available for about 4 months earlier this year... as they were
busy sorting out 5.6.
Fedora is RedHat's development release where they try stuff out - this is released
periodically, and is used as the foundation for a RedHat Enterprise release.
In a nutshell:
Redhat is enterprise ready server lots of testing before released, fully supported.
Fedora is cutting edge stuff - some of which may appear in a future release of Redhat
Centos is freebie Redhat Enterprise - they take source code, change Redhat names and Logos to
Centos and rebuild the systems - doesnt contain all the apps but good enough to run in
production. Stable but no Redhat support.
Oracle's Linux is also Redhat rebadged but with oracle specific patches added until they are
subsequently adopted by Redhat - fully supported by Oracle.