Receipts Trie

In Ethereum, a block contains a list of transactions, and each transaction can result in multiple changes to the state of the system, such as transferring ether from one account to another or modifying the state of a smart contract.

When a block is added to the blockchain, it also includes a list of receipts that correspond to each transaction, indicating the results of that transaction. The receipts include information such as the amount of gas used, the contract address created (if applicable), and the logs generated during the transaction.

The receipts are stored in a data structure known as the receipts trie, which is similar to the state trie and storage trie. The receipts trie is a Merkle tree that stores the transaction receipts in a compressed form.

Each node in the receipts trie represents a subset of the receipts, and the root node of the trie represents all the receipts in the block. The receipts trie is used to efficiently store and retrieve transaction receipts, and to prove the inclusion of a specific receipt in a block.

In summary, the receipts trie is a data structure used in Ethereum to store the receipts of transactions included in a block, and it is implemented as a Merkle tree.