Transactions are the fundamental building blocks of blockchain networks. They can represent a variety of activities, such as the transfer of cryptocurrencies, smart contract interactions, or any other data being logged on the blockchain. In most blockchain systems, a transaction will include certain details such as the sender's address, the recipient's address, the amount of value being transferred (if applicable), and a digital signature for verification. Transactions must be confirmed by the network through a process known as mining or validating, depending on the consensus mechanism in use (e.g., Proof of Work or Proof of Stake). Only confirmed transactions are permanently recorded on the blockchain, ensuring a tamper-resistant history of actions.