A concrete example
A 0.10 BTC input can fund a payment, a change output and a fee.
In context
If you control a 0.10 BTC output and send 0.03 BTC with a 0.0001 BTC fee, you can create a 0.03 BTC recipient output and a 0.0699 BTC change output. Inputs minus outputs equal the fee. These are illustrative amounts, not a live fee estimate.
Explore the full explanation
Bitcoin
Bitcoin UTXOs explained
Bitcoin records unspent transaction outputs, or UTXOs.
Beginner4 min reading + workshop ↗