Yeah it’s a deep rabbit hole. I’ve learned a ton on Stacker News! As you can tell based on this thread I’ve got a lot to learn, but the more I learn and adjust helps me sleep better at night!

Satosora

UTXO refers to Unspent Transaction Output (plural: UTXOs). Funds in the Bitcoin network are tracked in the form of individual UTXOs. Your wallet’s balance is the sum of the UTXO amounts it can spend, however, the total amount you can send from your wallet is lower, since you will need to pay fees on the transaction.

Here is a good link from a Stacker  for more details- https://stacker.news/items/298282/r/BitcoinIsTheFuture

And from Unchained - https://unchained.com/blog/what-is-a-utxo-bitcoin/