Bitcoin Script is a programming language used in Bitcoin transactions. It allows users to define the conditions under which bitcoins can be spent. This scripting language is stack-based, meaning it uses a last-in, first-out approach to evaluate commands. Transactions are made secure through scripts that can require various conditions to be met.

For example, a basic transaction script might specify that a recipient’s signature is necessary to unlock and spend the coins. More complex scripts can enable multi-signature requirements, time-locks, or other conditions. Scripts are embedded in Bitcoin transaction outputs, allowing for a wide range of functionalities. However, Bitcoin Script is intentionally limited in complexity to enhance security and maintain the simplicity of transactions.

It does not support loops or complex operations, which helps prevent certain types of vulnerabilities. Overall, Bitcoin Script plays a critical role in ensuring the robustness and flexibility of the Bitcoin network by allowing users to create custom transaction conditions while ensuring they remain secure and straightforward.