CentOS is short for Community Enterprise Operating System. This is one of the top Linux releases for servers and it's regarded as one of the most stable and protected Operating Systems on the market. CentOS is open-source software, so you can customize it in whatever way you see fit, adding and removing packages or modifying the program code of all of them. It's also free to distribute and use, so you will not have to pay any kind of license fees, which means that the total price that you'll need to pay for a server making use of CentOS will be much lower than the price for a server working with an alternative OS. What makes CentOS unique among various other Linux distributions is its huge developer community, that will help you get the reply to any question or problem you have. What's more, each version which is released officially is supported for a decade, that is is longer than with any alternative operating system. What this means is frequent protection and stability updates which provides a reliable software environment for all your web apps in the long run.