BNB Smart Chain Shared Node

BNB Smart Chain (formerly Binance Smart Chain) (BSC) is a decentralized system that operates in parallel to the Binance Chain (BC), with transfers and communication between nets. The BC mainnet was launched in April 2019. A year later, in the Binance Chain white paper, the exchange introduced the concept of another similar blockchain to support smart contracts.
As a result, BSC is a high-throughput blockchain with smart contracts. But it also has other specific functions:

• adapted to work with the Ethereum Virtual Machine;
• supports many of Ethereum tools and DApps;
• unique option: BNB staking.

Important note: BSC is not an “off-chain” system but a decentralized net. It is also not “layer two” but an independent blockchain quite similar to Binance Chain.

BC (Binance Chain) is “the home net” of BNB tokens. But due to cross-chain communications, they are also accepted in BNB Smart Chain. Speaking of nodes, there are two types of them in BSC:
Witness Node. Their functions in PoSA algorithm:

• participating in the consensus processing;
• keeping datasets in a consistent state;
• participating in distributed transactions;
• redirecting transactions to other BSC nodes;
• extending the chain characteristics and states around the whole net.

Most nodes in Binance blockchains are Witness.

Validator Node. It’s a group that validates all the transactions inside the blockchain. Originally, there were only 21 validators in BSC — node owners with special privileges, Binance community favourites. In the future, there will be more of them. But for running this type of node, special permission is required. Learn more from Binance paper.

BNB Smart Chain is built on a Proof-of-Stake consensus. More precisely, the algorithm’s name is Proof of Staked Authority (PoSA). BSC members stake BNB to become validators; the ones who made valid blocks get transaction fees. But, unlike many other ecosystems, new BNB tokens aren't produced with creating blocks. In contrast, the amount of currency decreases with time. Validators sign blocks that contain cryptographic signatures signed by each validator's private key. A certain set of validators is determined by a staking module and changes every day.

BSC has really low fees. In BSC, 1 gwei is 10-9 or 0.000000001 BNB. It’s the reason why it became popular and Ethereum-based DeFi sector has stagnated amid rising transaction fees. Nowadays, there is a major influx of users to the BNB Smart Chain. The Ethereum ecosystem is still developed better: it has plenty of asset marketplaces and derivatives. But BSC is expanding exponentially: SushiSwap was added recently, and some other updates have been announced. BNB (BNB Smart Chain token) grew by 374% by the end of February. According to market analysts, now ETH holders are selling their coins to buy BNB.