I just realized that quite a few people still don't really understand what a snapshot is, even though it is an extremely important concept in DeFi and blockchain. It’s not just a strange name, but the foundation of most major activities in crypto.

Maybe you've received an airdrop without knowing where the snapshot took place. For example, Uniswap in 2020 — they took a snapshot of the blockchain state on September 1, 2020, and used it to distribute 400 UNI to each wallet involved in transactions. That was one of the most historic airdrops in DeFi, and it could only happen thanks to a snapshot.

So what exactly is a snapshot? It is recording the entire blockchain state at a specific block — like taking a panoramic photo of the system at a certain moment. All wallet balances, token stakes, smart contracts, pending transactions — everything is recorded. Once the snapshot is complete, that data becomes immutable, no one can change or delete it.

Why is this important? Because it solves a big problem: fairness. Without a snapshot, anyone could wait until the last minute, buy tokens, and then claim an airdrop. Snapshots prevent that by “freezing” the data at a specific point in time.

I see snapshots appearing everywhere. Wormhole used a snapshot in February 2024 to determine who qualifies for W tokens — they looked at cross-chain transactions, PYTH staking, NFT ownership. Cardano uses snapshots after each epoch to distribute staking rewards for ADA fairly. Ethereum 2.0 also uses snapshots to calculate validator rewards.

Besides airdrops, snapshots are widely used in DAO governance. When Compound needs to change DAI interest rates, they base it on a snapshot of the COMP balances to determine each person’s voting rights. This prevents someone from buying tokens at the last second just to manipulate the voting outcome.

Another application I see less often mentioned is hard forks. When Bitcoin Cash was launched in 2017, they used a snapshot of Bitcoin to decide who would receive BCH. Everyone holding BTC received an equivalent amount of BCH. Snapshots ensure no one loses rights during the chain split.

DeFi protocols like Uniswap or Sushiswap also use snapshots to distribute profits from liquidity provision. Those who contribute more are recorded and rewarded accordingly. That’s why snapshots are considered the transparent ledger of the entire protocol.

Many people also worry: does a snapshot delete old data? The answer is no. Snapshots only record data at a specific moment; they do not interfere with the blockchain’s history. And if you sell tokens right after the snapshot, you still qualify for the airdrop because the data has already been recorded.

The beauty of snapshots is that they also apply to NFTs. Many projects use snapshots to distribute airdrops or other benefits to NFT holders. Security is not compromised — snapshots only record data, not interfere with transaction validation mechanisms.

In summary, what is a snapshot? It is a key tool to ensure transparency, fairness, and accurate distribution of benefits for everyone participating in blockchain. Whether you’re involved in airdrops, staking, DAO governance, or hard forks, snapshots are always there to protect your rights. Understanding this mechanism will help you avoid unnecessary mistakes and better seize opportunities in DeFi.