Transactions Trie

The Transactions Trie in Ethereum is a Merkle Patricia Tree (also known as a radix tree) that stores information about all the transactions in the blockchain. Each node in the tree represents a hash of a key-value pair, where the key is the hash of the transaction and the value is the transaction itself.

The Transactions Trie is structured in a similar way to the State Trie, with each node in the tree representing a portion of the hash of the key. However, instead of storing account state information, the Transactions Trie stores information about each individual transaction.

When a new transaction is submitted to the Ethereum network, it is first validated by the nodes on the network, and then added to the Transactions Trie. The transaction is added to the Trie by hashing its transaction ID, and then adding it as a key-value pair in the Trie. The transaction itself is stored as the value for the corresponding key.

The Transactions Trie is used by the Ethereum network to keep track of all transactions that have been submitted and processed by the network. When a new block is added to the blockchain, it contains a list of all the transactions that were included in that block. The Transactions Trie is used to validate that the list of transactions in the new block matches the state of the network, and that there are no conflicting transactions or double-spending attempts.