Glossary
Commitment Scheme
A cryptographic primitive that lets you commit to a value now and reveal it later, with no way to change the value between commit and reveal.
A commitment scheme has two properties: "hiding" (the commitment
reveals nothing about the value) and "binding" (you can't later
open the commitment to a different value). The simplest construction
is hash(value || nonce).
Commitments underpin many on-chain protocols: sealed-bid auctions, hash-time-locked contracts, randomness beacons, and KZG commitments for blob data. Anywhere you need to publish "I have decided" without yet revealing what, a commitment scheme is the primitive.