The title is terrible. Here is an excerpt from the article that explains what's going on: "The company's solution was to develop Git Virtual File System (GVFS). With GVFS, a local replica of a Git repository is virtualized such that it contains metadata and only the source code files that have been explicitly retrieved. By eliminating the need to replicate every file (and, hence, check every file for modifications), both the disk footprint of the repository and the speed of working with it were greatly improved. Microsoft modified Git to handle this virtual file system. The client was altered so that it didn't needlessly try to access files that weren't available locally and a new transfer protocol was added for selectively retrieving individual files from a remote repository."

This style of working is needed in large code bases, where not all files are checked out on developer workstations (for performance or privacy reasons).