Now, let's have a look at the programmability aspect of Bitcoin. Some blockchain cryptocurrencies are referred to as programmable money.

Bitcoin is indeed a programmable digital currency. It uses a programming language called Script in structuring and processing transactions. As the name suggests, this is a script type of language, which supports small programs called scripts. They automate the execution of a list of tasks, or commands, that otherwise could be executed one-by-one manually by a human operator.

Script is a high-level programming language with limited functionality, which is also domain-specific, meaning it's specialized to its application domain. Bitcoin's transaction script was specifically designed to be limited in scope, in order to require minimal processing and to be executable even on very simple devices. Its...