RHEL 5 vs RHEL 6 ?

RHEL 5 vs RHEL 6 ?

If by any chance you are appearing for an interview for a position if Linux Administrator then the most common question which is asked is what is the difference between RHEL5 and RHEL6 ?

• Visualization: In RHEL 6 KVM (Kernel based Virtual Machine) was used as a hyper visor but in the earlier releases of RHEL XEN was used as a hypervisor. The main advantage of KVM is that it supports the installation of many virtual machines/operating systems like Windows, Linux, Solaris and also it is very easy to manage those virtual machines.
• Security: RHEL6 has an enhanced version of SELinux(Security Enhanced Linux) now, Basically now the features are more improved and there are various new set of rules which are added to SELinux one of such rule/feature is of SVirt which provides security to virtual machines from hackers.
• EXT4: It stands for Extended 4, It has various new advantages then EXT2/3 which were used in earlier version(s) of RHEL. EXT4 is comparatively more faster and easy to manage then previous file systems.
• IPv6: RHEL6 supports IPv6.
• NFS4: It uses NFSv4 (Network File Transfer) the latest version of NFS for the sharing of files in the network rather than NFSv3.
• GUI: It has a far better GUI(Graphical User Interface) then RHE5 or any of its prior version(s).

What are the main differences between RHEL4 & RHEL5 and RHEL 6

#########RHEL4 and RHEL 5 ######################## 
XEN, YUM and improved SELinux
all the features updated with better options
Better GUI support then RHEL4
YUM over RPM package management
IPTables and SELinux for more secure environment
ext2 & ext3 file system
In RHEL 4 SELinux Block only 13 services, But on RHEL 5
SElinux Block 80 services
 ############################################### Difference between RHEL 4 and RHEL 5 : 1) In RHEL 4 SELinux Block only 13 services, But on RHEL 5 SElinux Block 80 services. 2) RHEL 4 have ext2 filesystem, but RHEL 5 we have ext3 filesystem that support Journal. 3) RHEL 4 have no virtualization Feature, but in RHEL 5 we have virtualization with Hypervisor-V. 4) In RHEL 4 we have no Yum, But in RHEL 5 we have Yum available.#####################################################