CentOS is an abbreviation for Community Enterprise OS. This is one of the top Linux distributions for servers and it's regarded as one of the most reliable and risk-free Operating Systems on the market. CentOS is open-source software, so you will be able to personalize it in any way you see fit, adding and removing packages or modifying the code of any of them. It's also free to distribute and use, so you will not have to pay any license fees, meaning that the overall price that you'll need to pay for a server making use of CentOS will be cheaper as compared to the price for a server running some other OS. What makes CentOS unique among other Linux distributions is its huge developer society, that will help you discover the answer to any kind of question or problem you have. In addition, each version that is released officially is supported for 10 years, which is much longer than with any alternative operating system. What this means is routine protection and stability updates which will provide a reliable software environment for all your web apps in the long run.