When drawn on paper, this is a 2D representation of the three dimensions. For example, when you draw a cube on a sheet of paper, this is still 2D, but it is a 3D representation, unlike a drawing of a square. 3D movies are labeled as 3 dimensional, but they are really just a 3D representation of a 2D object.
In July 2010, CentOS overtook Debian to become the most popular Linux distribution for web servers, with almost 30% of all Linux web servers using it. Debian retook the lead in January 2012.
In addition to installing CentOS, there is one other option that will allow you to try out CentOS without physically installing it to a disk drive. This is achieved by using the CentOS Live CD. This is essentially a copy of CentOS that can be run from the DVD/CDROM drive of your system.entOS can be installed either in a clean disk environment (where an entire disk is dedicated to CentOS) or in a dual boot environment where CentOS co-exists with another operating system on the disk (typically a member of the Microsoft Windows family of operating systems).