CoreOS versus other Linux distributions

Even though CoreOS is yet another Linux distribution like Fedora/Centos, the key difference between CoreOS and other standard Linux distributions are as follows:

• CoreOS is not designed to run any applications or services directly. Any application to be run inside CoreOS should be deployed as a container (which can either be Docker/Rocket). So it is not possible to install any software packages in CoreOS and hence CoreOS doesn't have any installation software packages like yum, apt, and so on. In short, CoreOS is a stripped-down version of a Linux distribution that doesn't have any inbuilt user applications or library installed.
• Most of the Linux distributions are meant to run as a host operating system either in a data center server or in a typical desktop PC. They are not developed to manage a cluster of nodes/the cloud; rather, they will be part of the cloud that is being managed by other cloud orchestration platforms. However, CoreOS is a Linux distribution that is builtout for the management of a massive server infrastructure with clustering. The CoreOS cluster is a group of physical or virtual machines that runs CoreOS with the same cluster ID. The services running in the cluster nodes are managed by fleet, which is the CoreOS orchestration tool. Software updates in a traditional Linux distribution are done by updating the packages one by one. However, CoreOS supports a scheme called fast patch, wherein the entire CoreOS OS is updated once. The CoreUpdate program is used for updating CoreOS in a server, cluster, or complete data center.
• CoreOS is extremely lightweight when compared to traditional Linux distributions.