WSL is a compatibility layer for running Linux binary executables (in ELF format) natively on Windows 10.
WSL provides a Linux-compatible kernel interface developed by Microsoft (containing no Linux kernel code).
The Windows Subsystem for Linux (WSL) is a new Windows 10 feature that enables you to run native Linux command-line tools directly on Windows, alongside your traditional Windows desktop and modern store apps.
WSL provides an application called Bash.exe that, when started, opens a Windows console running the Bash shell.
WSL cannot run Linux apps. WSL is a tool aimed at enabling users who need them to run Bash and core Linux command-line tools on Windows.
WSL does not aim to support GUI desktops or applications (e.g. Gnome, KDE, etc.)