A shade twin is someone who wears the same foundation/ makeup product shade as you! Meaning you share similar skin tone and undertones. This list will help you find high-end and drugstore dupes for your foundation if you are my shade twin! :) For ref...
Shade N5
True Match Super-Blendable Foundation - L'Oréal Paris
250 Light Medium Neutral - neutral peach undertones
triclone™ skin tech medium coverage foundation
Shade 4 Medium
Halo Glow Liquid Filter Complexion Booster
Shade Latte 300N
Easy Blur Natural Airbrush Foundation with Niacinamide
Shade 4.5 Medium Golden beige
Hollywood Flawless Filter: Glow Booster
Shade 7 Medium Neutral
Milk Makeup Hydro Grip 12-Hour Hydrating Gel Skin Tint
Shade 5N Medium with Neutral & Subtle Olive Undertones
KYLIE COSMETICS - Skin Tint Blurring Elixir Foundation