Blockchain technology is primarily employed for online transactions, as it forms and maintains an immutable distributed ledger based database for every online transaction. The online transactions utilize two familiar blockchain transaction protocols that are as follows
  •  Unspent Transaction Outputs (UTXO)
  •  Account-based Transaction
•  UTXO Model: Bitcoin technology presents the first UTXO model. The UTXO transaction model allows users to store the received bitcoins as unspent instances. That means the user receives the coins successfully but has not spent the coins for transactions. By exploiting the UTXO transaction model, the users can record the total Bitcoin transaction history of the network.
•  Account-based Transaction: Firstly, Ethereum integrates the account-based online transaction strategy, a simpler model. It exploits the information of user account for online cryptography transaction. It explicitly completes the online transactions based on the accounts of the sender. Moreover, the main intention of account-based transactions is to enhance the efficacy of consensus and increase the block times at a higher risk cost.