For an exampel if I preveiw a transaction where the send amount is 0.12 BTC with a fee of 0.00004 and preciew another transaction where the send amount is 0.19 BTC with a fee of 0.00004 then "Sum of outputs" of both the preciews is 0.2 BTC. I guess that I once had an input of 0.2 BTC?
However, is this wrong? Should it be 0.12 BTC + fee as an output and 0.19 BTC + fee?
I don't know if it matters but I restored my armory wallet. If I hover the question mark of the "sum of outputs" it says:
"Most transactions have at least a recipient output and a return-change output. You do not have enough information to determine which is which, and so this fields shows the sum of all outputs".
My armory is online and I can make transactions with it. Wallet version is 1.35
A bitcoin transaction is broken down into 2 section.
1) Inputs point to previous outputs, they redeem the entire value of their respective output and make these available to the transcation
2) Outputs assign the available balance to new recipients. Any value that is no assigned is burned as fee.
The "sum of outputs" field informs you about how much BTC was redeemed by the transaction's inputs. The wallet assigns your spend value to the payment address, and the left over back to one of your addresses as change. In the transaction detail dialog you can see the change as greyed out.
You should always compare the sum of outputs value vs what you are paying, and if they differ, make sure your transaction has a change output. These are the baseline steps to verify your transaction before signing, besides double checking the payment address and spend value.
Armory is a good wallet, but there are many better imo. Electrum.org is a better one and electrum allows you to see each input you have (it is called Coin, in coin tab)
Armory had coin control before Electrum had deterministic wallets.