One thing to remember about Unix/Linux, vs. Windows, is that there is no "all-encompassing 'system registry.'" Instead, information is kept in discrete files at well-known locations.
But another thing to bear in mind is that "Unix/Linux" is a very broad range of deployments. It runs on more than 25 wildly different types of computers, from cell-phones to mainframes. There are "secure" and "hardened" systems, ones that are designed to control clusters of machines, and on and on. Per contra, Microsoft Windows runs only on a small handful of system-types, and every one of them is comparatively small. Whereas Windows has "one way to do things," in Unix/Linux: "TMTOWTDI = There's More Than One Way To Do It."