A partially signed Bitcoin transaction, or PSBT, is a type of Bitcoin transaction that is only partially signed. It is a way of representing a Bitcoin transaction that is in the process of being signed by multiple parties. A PSBT contains all of the information that is needed to complete the transaction, such as the inputs and outputs, the scripts and other conditions that must be satisfied, and the signatures of some, but not all, of the parties involved. A PSBT is typically created by a wallet software, and it is then sent to one or more other parties for signing. Once all of the required signatures have been added, the PSBT can be finalized and broadcast to the Bitcoin network.