A UTXO is like a single bill. In bitcoin the bills can be any size, in dollars they're only specific sizes.

The bitcoin network is like a bank teller. You can take 2x $5 bills to the bank and get back a $10. Or split a $10 into two $5s.

I can pay you $15 either by

• Giving you a $10 and a $5 and getting no change.
• Giving you 2 $10s and getting a $5 back.
• Giving you a $20 and getting a $5 back.

In bitcoin the bills can be any size. $1, $2, $3, $4, $5, etc. but it works the exact same way.