Starting with Unity 2018.1, Unity Technologies introduced new Project Templates. The 2D and 3D project templates have been a part of Unity for years, but now there are additional ones. They include the following:
- 3D with Extras
- Lightweight Render Pipeline
- VR Lightweight Render Pipeline
- High Definition Render Pipeline
- AR Basic
- AR Sample
Each one has its own strength and weaknesses. High Definition Render Pipeline has the best graphics, but requires a lot of computing power.
If you are doing work for the HoloLens, you probably want to stick with the Lightweight Render Pipeline or just 3D.
If you are using an immersive mixed reality headset / VR headset, you probably want the VR Lightweight Render Pipeline.
You can see Unity’s official blog post which has more information here.