Transaction

An entry in the blockchain ledger which describes the exchange of an asset from a set of input addresses to a set of output addresses.
Each transaction must also include a small extra amount for the miner to confirm the transaction - known as the miner fee.

Transactions on the blockchain can take many forms, and can be crafted in thousands of ways. The most typical transaction is one person sending funds to another person. But there's a lot of flexibility to these.

Multiple addresses can contribute inputs to a transaction, multiple addresses can receive the outputs of the transaction.
There's extra space in transactions to write additional data, which second layer protocols may use - such as SLP tokens.