[2] It was one of the first debuggers for MS-DOS to be full-screen oriented, rather than line-oriented (as Microsoft's predecessors DEBUG and SYMDEB or Digital Research's SID).
Variants like -Zs and -Zd provide lesser information, and smaller output files which, during the early 1990s, were important due to limited machine resources, such as memory and hard disk capacity.
CodeView version 3.x and 4.x introduced various transport layers, which removed some of the memory space limitations to this form of symbolic debugging.
CodeView also came with a CVPACK command-line utility, which can reduce the size of the CodeView-generated information internally, while still retaining full symbolic access to data.
Today, the debugger is considered an integrated and essential part of the Microsoft Visual Studio family of products, and owes its true roots to CodeView, and the enhancements seen in version 4.x specifically.