41 ADA skimmed from 265 ADA xfer from Coinbase

I sent ADA from Coinbase to Yoroi. Coinbase transaction fee indicated it would cost .18 ADA. After sending the ADA, I noticed 41 ADA had been sent to another address. Can someone explain to me what just happened???

Transaction Hash: b099c2ae006c40ef15317cc33dad580ebfac93d1dead435433ccabe9b4f5b4c1


Coinbase sent you 223 ADA and the 41 ADA went back to Coinbase as change. You can see that they went to the same address that the complete 265 ADA were coming from.

In the model used by Cardano (but also Bitcoin), the only way to transfer some assets is to completely spend the outputs of previous transactions that you received. If they do not fit the amount that you want to send (which will nearly always be the case) the rest comes back as change to one of your own addresses.

If you would now want to send 10 ADA to someone, your wallet app would only find the output with 223 ADA from Coinbase. So the transaction would have an input of 223 ADA and outputs of 10 ADA to the other person and 213 ADA back to one of your own addresses.

The advantage compared to an account-based model is that the nodes in the network only need to check a local property (“Are the inputs of the transaction still unspent?”) instead of a global property (“What is the balance of this account?”).

Thanks. That makes sense now.