Twitch Drops are items which you can redeem for a limited time by watching streamers streaming Overwatch 2. Usually, each drop takes around 1-3 hours of watch time to redeem. More on how to earn drops here.
These redeems can be things such as: Sprays, Highlight intros, Voice lines, Skins, Player Icons, Name Cards, Weapon Charms and even Battle Pass Tier Skips.
Most of the time these redeemable items are themed to current the season, event or even a new hero. However, sometimes there are unrelated and even shop skins and cosmetics up for grab.
Some items may only be redeemable on certain channels, such as Overwatch Contenders and Overwatch League skins/cosmetics.