What are the display modes for The Last of Us Part II Remastered and what do they mean?

The available display modes for The Last of Us Part II Remastered are:

Fidelity - Favor resolution over framerate

• Rendered and output at 4k
• Target 30 fps 

Performance - Balanced resolution and framerate

• Rendered at 1440p, then output at upscaled 4k or 1440p (depending on Video Output console settings)
• Target 60 fps

Unlocked Framerate - Maximizes framerate on supported televisions.