Initialism of content management system.
"The engineer measured the pipe and noted that its diameter was exactly 5 cms."
plural of cm; centimeters
In plain English: A CMS is a program that helps you create and manage website content without needing to know how code works.
"The new website is now live on all three cms platforms we use for content management."
Initialism of Chicago Manual of Style.
"The editor consulted the CMS guidelines to ensure proper citation formatting throughout the manuscript."