So, Robinhood (one of the largest trading apps in North America), have opted to use Polygon over Ethereum for their Web3 wallet.

But what does that mean - and why does it even matter?

Remember how we spoke about 'layer 2's' in our first article? Polygon is a layer 2 built on Ethereum, the same way the Lightning Network is a layer 2 built on Bitcoin.

But let's dig a little deeper and clear some things up...

How can it be 'built on' Ethereum - without using Ethereum?

Think of Ethereum as an operating system (OS), and Polygon as an app built on that operating system.

They interact similar to the iPhone and the mobile apps built on it. The iPhone OS provides optional security (passcodes & Touch/Face ID) and the apps provide specific functionality.

Ok, great. We're halfway there! Now...

You know how some iPhone apps aren't password protected by default, but let you switch on 'Open with Face ID'?

It slows things down when trying to access the app, but it means even if your phone is unlocked, there's still another layer of security that needs to be passed in order to open it.

The same thing happens with Ethereum and Polygon.

Users can process their transactions, fast and cheap, solely on the Polygon Network with a little less security (great for smaller transactions).

But if they want to beef up their protection, they can opt to pay a little extra / wait a little longer, and use Ethereum's security (great for larger transactions, where a $1-10 transaction fee is a drop in the bucket).

Ok, cool...so why does it matter that the Robinhood team are using Polygon to build their Web3 wallet?

Because most end users don't care about all of the mechanics we just went over - the only thing they'll notice is whether it's cheap and easy to use.

And a Polygon wallet, built by Robinhood will tick both of those boxes.

Now you know!