2 addresses? one a mystery?

[truebits]

Hi

I came across a mystery today when I went to move some Bitcoin out of Armory that had been parked for years.

The first transaction went through without a glitch and it was FAST too!

Second transaction I created, on the online computer, then go to sign that transaction on the offline computer and get this weird message that you are sending this to 2 addresses (which I am not) so I DID NOT approve it and instead I am posting it here. (link below).

So I add my address where I am sending my stuff to, the one starting with 39U1AzG***************
Then I go to confirm the transaction and this second address shows up (3MxaTKLroUitGF8yftF5VQTEsdtm26xb3Z),  I have no idea where that came from, and I do not recognize it (photo link below, the bottom address in the photo is mine and I do recognize it).

I looked these up on the https://www.blockchain.com/ and see no transactions under Bitcoin or Bitcoin cash for address (3MxaTKLroUitGF8yftF5VQTEsdtm26xb3Z)?

ideas what is going on here?

How can I clear the second address? I tried restarting my computer and Armory AND Bitcoin core, nothing changed?

Link:

https://imgur.com/a/KFGQFEW

[hosseinimr93]

3MxaTKLroUitGF8yftF5VQTEsdtm26xb3Z is your change address. This means that the address is used for receiving the remaining balance of selected UTXOs.

Let's say you have received 1 BTC in a transaction and you want to send 0.4 BTC to address A.
You can't send the 0.4 BTC without touching the other 0.6 BTC. Therefore, your wallet sends 0.4 BTC to address A and sends 0.6 BTC (- fee) to your change address.
Note that you own 3MxaTKLroUitGF8yftF5VQTEsdtm26xb3Z as well.

[truebits]

Thank you!

[HCP]

You should be able to confirm that it is indeed your change address by clicking "Wallet Properties" and then expanding the "Change addresses" section. You should see the 3MxaTKLroUitGF8yftF5VQTEsdtm26xb3Z address listed in there.

[truebits]

You should be able to confirm that it is indeed your change address by clicking "Wallet Properties" and then expanding the "Change addresses" section. You should see the 3MxaTKLroUitGF8yftF5VQTEsdtm26xb3Z address listed in there.

So the fee of 0.078 goes back into my account for address 3MxaTKLroUitGF8yftF5VQTEsdtm26xb3Z?

[HCP]

It's not a fee... it's your "change"...

Think of it like you went to the store and bought something for $12 with a $20 note... you get $8 "change"... Most bitcoin wallets will automatically assign any change to a new address. In your instance, Armory has generated the address 3MxaTKLroUitGF8yftF5VQTEsdtm26xb3Z and assigned the 0.078 BTC change to that address.

More info on "change": https://en.bitcoin.it/wiki/Change