[balls187]

You can play the PSP in your handheld and connected your TV.

With the Switch you can use it docked, handheld, and tabletop (i.e. stand alone).

[Gigablah]

Speaking of docking, there was this phone + tablet hybrid from Asus: https://www.asus.com/us/Phone/ASUS_PadFone_X_US/gallery/