Stack of Transactions / Mempool

In Ethereum, a stack of transactions refers to the group of transactions waiting to be included in the next block of the blockchain. This stack is commonly referred to as the transaction pool or mempool.

When a user initiates a transaction on the Ethereum network, it is broadcast to all nodes on the network and added to the transaction pool. The transaction pool contains all valid transactions that have not yet been included in a block.

Miners on the network will then choose which transactions to include in the next block based on a number of factors such as the gas price offered and the overall size of the block. Once a transaction is included in a block, it is removed from the transaction pool.

The stack of transactions is important because it represents the current demand for transaction processing on the network. If the stack is large, it can indicate high network usage and potentially higher fees for users.