CentOS is short for Community Enterprise Operating System. This is one of the leading Linux releases for servers and it is recognized as being one of the most reliable and secure Operating Systems out there. CentOS is open-source software, which means that you'll be able to customize it in whatever way you see fit, adding and removing packages or updating the code of any of them. It is also free to distribute and use, so you won't need to pay any kind of license fees, meaning that the overall price that you'll have to pay for a server running CentOS will be much lower than the price for a server running an alternative OS. What makes CentOS unique among various other Linux distributions is its huge developer society, that will help you get the answer to any kind of question or problem you might have. What's even more, each version that is released officially is supported for ten years, that's is longer than with any alternative OS. This means ordinary security and stability updates which provides a stable software environment for all your web applications in the long run.