How Do Blockchains Verify Transactions?
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Blockchain consensus is the way all the computers in a blockchain network work together to agree on which transactions are real and should be added to the chain. Because no single person or bank is in charge, the computers must check every transaction and vote on it to keep the system fair and safe. Blockchains use methods like Proof-of-Work, where computers solve puzzles, and Proof-of-Stake, where computers are chosen based on how many tokens they hold, to decide who adds the next block. Once everyone agrees, the new block becomes permanent, helping blockchains stay honest, secure, and trusted by everyone who uses them.
What Does Consensus Mean & How Does It Work?
Blockchain consensus is the way all the computers in a blockchain network agree on what is true. Because there is no single boss or bank in charge, all the computers must work together to decide which transactions are real. Consensus is important because it makes sure everyone sees the same information and that no one can cheat by making fake transactions. It keeps the blockchain fair, honest, and safe for everyone using it. The two most popular ways blockchains stay safe are Proof-of-Work (PoW), where computers solve hard puzzles to add new blocks, and Proof-of-Stake (PoS), where computers that hold more tokens get chosen to help add blocks and keep the network secure.
To reach consensus, the computers in the network check every new transaction. They look to see if the person sending digital money actually owns it and if the transaction follows the rules. Only if most of the computers say “yes, this is correct” can the transaction be added to the blockchain. This team effort helps keep bad or false information from getting in. It’s like a group vote where everyone helps decide what gets written down.
Different blockchains use different methods to reach consensus. One method is called Proof-of-Work, where computers solve hard math puzzles to earn the right to add the next block. Another method is Proof-of-Stake, where computers are chosen to add blocks based on how many tokens they hold. Even though they work differently, both systems make sure no single person is in control and that everyone follows the same rules.
Once consensus is reached and a new block is added, it becomes part of the permanent chain and cannot be changed. If someone tried to cheat by changing a block, the network would quickly see the error and reject it. Consensus is what keeps the blockchain trustworthy, making sure every user sees the same history and knows the system is working correctly.
How Do Blockchains Verify Valid Transactions and Reject Invalid Transactions?
Blockchains verify valid transactions by having many computers, called nodes, check each transaction before it is added to the chain. When someone sends digital money, the nodes look at the transaction to make sure the sender actually has enough funds and has the right digital key to spend it. This is like checking if someone really owns the money before they are allowed to send it. If everything looks correct, the nodes agree that the transaction is valid.
To stop cheating, blockchains also make sure a person can’t spend the same money twice. This is called solving the “double-spend” problem. The double spend problem is when someone tries to use the same digital money more than once, and cryptocurrencies solve this by having many computers check and agree that each coin can only be spent one time. Every time a transaction is sent, the nodes compare it to all the earlier transactions stored on the blockchain. If they see that the money has already been used, they reject the new transaction right away. This keeps the system honest and prevents fake spending.
After checking each transaction, the nodes work together to decide which transactions should be added to the next block. This teamwork is called consensus, and it makes sure everyone agrees on the same version of the blockchain. Once a transaction is approved and added to a block, it becomes part of the permanent record and cannot be changed. This protects the system from lies or mistakes.
Invalid transactions get rejected automatically. If a transaction has the wrong digital signature, tries to spend money that doesn’t exist, or breaks the rules of the blockchain, the nodes will not accept it. They simply refuse to add it to the chain. This process helps blockchains stay fair, safe, and trustworthy, because only real and honest transactions are allowed into the system.
What’s The Difference Between Mining and Staking?
Mining and staking are two different ways that blockchains stay safe and add new transactions, but they work very differently. Mining is used in blockchains like Bitcoin. In mining, powerful computers race to solve hard math puzzles. The first computer to solve the puzzle gets to add the next block of transactions to the blockchain. As a reward, the miner earns new digital coins. Mining uses a lot of electricity because the computers must work very hard and very fast.
Staking is used in blockchains that don’t need those big math puzzles. Instead of using powerful computers, staking lets people lock up some of their digital coins to help secure the network. When someone stakes their coins, the blockchain may choose their computer to add the next block of transactions. The more coins someone stakes, the higher the chance they get chosen. If they follow the rules, they earn a reward. Staking uses much less energy than mining.
The main difference is how each system picks who gets to add the next block. Mining picks the winner based on computer power, whoever solves the puzzle first gets the job. Staking picks based on how many coins are locked up and how long they’ve been staked. Because of this, staking doesn’t require expensive machines and is easier for more people to join.
Both mining and staking help keep blockchains safe and make sure transactions are checked and approved. Mining protects the network with strong computer power, while staking protects it by having users commit their coins and follow the rules. Even though they work differently, both systems make blockchains fair, secure, and trustworthy.