At one point I tried to visualize it on paper but a few lines of hex characters isn't satisfying. Essentially it's the ability to spend that much bitcoin in the future.

We call it an unspent transaction output (utxo) and it's value is being able to turn it into a spent output, pay miner fees, and create new utxos owned by yourself or someone you're paying.

Stepping further back you can think of a utxo as a slice of the future economy, a vote of confidence, a share of a decentralized organization, or one of many other things that we'll discover over decades.