Joy-Con is a mix-and-match controller for the Nintendo Switch. The Nintendo Switch Lite doesn't have any Joy-Cons. The Nintendo Switch OLED has glacier-white Joy-Cons. Joy-Cons are known for 'drifting'. There is special alternative to the Joy-Con that can be used in Pokemon: Let's Go Pikachu! or Pokemon: Let's Go Eevee! called Pokeball Plus.
Nintendo Switch (OLED Model)/Gallery, Wikitendo Wiki
File:Nintendo-Switch-JoyCon-Rail.jpg - Wikimedia Commons
Nintendo Switch Joy-Con The Legend of Zelda Skyward Sword Edition JAPA — ToysOneJapan
Nintendo Switch - Super Mario Wiki, the Mario encyclopedia
Joy-Con, Wikitroid
Best Buy: Nintendo Joy-Con (L)/(R) The Legend of Zelda: Skyward Sword HD Edition HACAJAUAE
Joy-Con, Smashpedia
Special Edition Joy-Con - Nintendo Switch Guide - IGN
Every Nintendo Switch Joy-Con Controller
Every Nintendo Switch Joy-Con Controller