What is silica gel and why do I find little packets of it in everything I buy?

Many of the things I buy contain little packets of crystals. Some of them actually say 'Silica Gel' on them, but many are unlabeled or say something like, 'Do not eat.' I have found these packets in electronics, vitamins and even in some pepperoni I bought last week! What is this stuff? Is it poisonous?
Many of the things I buy contain little packets of crystals. Some of them actually say "Silica Gel" on them, but many are unlabeled or say something like, "Do not eat." I have found these packets in electronics, vitamins and even in some pepperoni I

Moisture Absorbing Silica Gel for Safes

Sachet indicating 20g - Buy online at Silica gel Shop

TIL that silica gel packets aren't poisonous. They are labeled do not eat because they are a choking hazard. : r/todayilearned

Moisture Absorbing Silica Gel for Safes

Woman Shares Why You Shouldn't Throw Out Silica Gel

Silica Gel – you only need to follow half of the directions. (Just ignore the other half.) - The V Spot

What is silica gel and why do I find little packets of it in everything I buy?

What Happens If You Eat Silica Gel? Adults, Children, and Pets

11 Unexpected Uses for Silica Gel Packets « The Secret Yumiverse :: WonderHowTo

Don't Be Afraid of Silica Gel Packs—You Can Do Cool Things with Them!

Silica Gel Packets + 50 Surprising Ways to Use Them