Think of a Waveshell as a multi-tool. The physical handle is the .vst3 file. The different screwdrivers, knives, and bottle openers that pop out of the handle are your individual plugins (Q10, Renaissance Reverb, L2 Limiter).
This is the product name. Every Waves version uses a "WaveShell" file for every format (AAX, AU, VST2, VST3). vst plugin waveshellvst3 92x64 vst3
It manages licensing and ensures only activated plugins are visible to your host software. Think of a Waveshell as a multi-tool