Bitcoin Script is a programming language that is used to define the rules for transactions on the Bitcoin network. It is a simple, stack-based language that allows developers to write scripts that specify conditions for spending Bitcoin. For example, a script might specify that a certain number of signatures from a group of people are required in order to spend some Bitcoin (see “multisignature”), or that a payment can only be made if a certain condition is met. Bitcoin Script is used in the creation of smart contracts on the Bitcoin network, which are self-executing contracts with the terms of the agreement between buyer and seller being directly written into lines of code.