# Concepts

- [What's Stereoscopic AR?](/product/concepts/whats-stereoscopic-ar.md)
- [Mixed Reality Spectrum](/product/concepts/whats-stereoscopic-ar/mixed-reality-spectrum.md)
- [OST vs VST](/product/concepts/whats-stereoscopic-ar/ost-vs-vst.md)
- [Why We Design HoloKit X?](/product/concepts/why-we-design-holokit-x.md)
- [Why iPhone Only?](/product/concepts/why-iphone-only.md)
- [Journey of HoloKit X](/product/concepts/journey-of-holokit-x.md)