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

LotFancy Silica Gel Desiccant Packets Dehumidifier, 100 Gram, 7 Packets, Rechargeable

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

Why Didn't I Do This Earlier? Reusing Silica Gel Packets – A Pretty Happy Home

Silica gel - Wikipedia

What To Do With Your Silica Packets – Sustainably Motivated

Don't throw them out! This is what you can do with those gel sachets that come in your shoe box

Definition of silica gel

What Are Silica Gel Packets And Is It Harmful If You Eat One?

What is Silica Gel? Definition, Uses, & Safety Information

Creative Ways to Reuse Silica Gel Sachets