CentOS is an abbreviation for Community Enterprise Operating System. This is one of the leading Linux distributions for servers and it's regarded as one of the most stable and protected Operating Systems available. CentOS is open-source software, which means that you can personalize it in whatever way you see fit, adding and removing packages or changing the code of all of them. It's also free to distribute and use, so you won't have to pay any kind of license fees, meaning that the overall price that you will need to pay for a server making use of CentOS will be lower than the price for a server running some other OS. What makes CentOS unique among various other Linux releases is its huge developer community, which will help you find the answer to any kind of question or problem you might have. Furthermore, each version which is released officially is supported for a decade, that is is longer than with any other operating system. What this means is routine protection and stability updates which will provide a reliable software setting for your web apps in the long run.