When RHEL is released, there are two ways. One is a binary distribution method, and the other is a source code distribution method.

No matter which distribution method is used, you can obtain it (for example, download it from the Internet) and publish it again. But if you use their online upgrades (including patches) or consulting services, you have to pay.

RHEL has always provided source code distribution. CentOS recompiles the source code released by RHEL to form a usable binary version. Since the source code of LINUX is GNU, it is legal to obtain the source code of RHEL and compile it into a new binary. It's just that REDHAT is a trademark, so the REDHAT trademark must be removed in the new release.

REDHAT’s attitude towards this kind of distribution is: “We are actually not opposed to this kind of distribution. What the users who really pay us value is not the system itself, but the business we provide. Services."

So, CentOS can get all the features of RHEL, even better software. However, CentOS does not provide commercial support to users, and of course it does not assume any commercial responsibility.