The is a proprietary wrapper technology developed by Waves. Instead of installing hundreds of individual .vst3 files for every single plugin (like the SSL E-Channel or H-Delay), Waves uses a single "Shell" file.
Upgrading to the V13 version of the WaveShell brought several technical advantages: vst plugin waveshell1-vst3 13.0-x64 -vst3-
It ensured stability for users moving to the Microsoft Windows 11 operating system. The is a proprietary wrapper technology developed by Waves