Interface TxOut

The datum value can also be inlined in the output revealing the value on the blockchain at the time of output creation. This way of attaching datums lets users consume this output without specifying the datum value.

Datum hash, this allows to specify a Datum without publicly revealing its value. To spend an output which specifies this type of datum, the actual Datum value must be provided and will be added to the witness set of the transaction.

Reference scripts can be used to satisfy script requirements during validation, rather than requiring the spending transaction to do so. This allows transactions using common scripts to be much smaller.

The key idea is to use reference inputs and outputs which carry actual scripts ("reference scripts"), and allow such reference scripts to satisfy the script witnessing requirement for a transaction. This means that the transaction which uses the script will not need to provide it at all, so long as it referenced an output which contained the script.