Volkswagen: What is Apple CarPlay & Android Auto?

What exactly is Apple CarPlay and Android Auto. Do I really need it? Which Volkswagen models have it and which smartphones are compatable?

How much data will I use on Apple CarPlay and Android Auto? - Drive

Volkswagen Touareg (2010 - 2018) Apple CarPlay & Android Auto Integration Kit

6.5"Car Stereo RCD330 +Frame CarPlay MirrorLink BT USB RVC For M – SCUMAXCON Official Store

Volkswagen Apple CarPlay & Android Auto Modules – Car Tech Studio

Vw214U

VW T5.1 RCD360+ With Apple Car Play / Android Auto 6.5 Factory Fit 10 – Travelin-Lite

How To Retrofit Android Auto/Apple CarPlay RCD330 In VW Golf MK6

Wireless CarPlay Android Auto for Volkswagen VW Polo Golf Touareg Tig – carlinkitbox

JoyeAuto CarPlay Retrofit Box for Volkswagen Touareg RNS850 2010-2017 8Android Auto Wireless Apple CarPlay Vw Navigation Mirror - sdsarabia

VW Android 12 Apple CarPlay & Android Auto Car Radio

Vw Golf mk7 apple carplay and android auto 06 - Automotive Control Bristol