It&#x27;s an architecture called z&#x2F;Architecture, used for z Systems CPUs such as the z13 CPUs in IBM mainframes (the z13, same name). The &#x27;z&#x27; in &#x27;IBM z Systems&#x27; stands for &#x27;zero downtime&#x27;.<p>[1] <a href="https:&#x2F;&#x2F;en.wikipedia.org&#x2F;wiki&#x2F;Z&#x2F;Architecture" rel="nofollow">https:&#x2F;&#x2F;en.wikipedia.org&#x2F;wiki&#x2F;Z&#x2F;Architecture</a><p>[2] <a href="https:&#x2F;&#x2F;en.wikipedia.org&#x2F;wiki&#x2F;IBM_z13_(microprocessor)" rel="nofollow">https:&#x2F;&#x2F;en.wikipedia.org&#x2F;wiki&#x2F;IBM_z13_(microprocessor)</a>