It's a free, community project A Computer system is a set of hardware and software that processes data in a meaningful way. A relatively complex computer system is the Internet . But the real meaning of computer system comes with interconnexion.
Many computer systems can interconnect, that is, join to become a bigger system.
Interconnecting computer systems is tricky, in the best of cases, due to incompatibilities, sometimes hardware and sometimes software. We can say that the natural inclination of computer system is not to interconnect themselves. This outside view effectively defines the way a system connects with another. If your system obeys with all the rules, it can be said to comply with the standard.